Ford Escape: Anti-Lock Brake System (ABS) and Stability Control / Diagnosis and Testing - Anti-Lock Brake System (ABS) and Stability Control

Normal Operation and Fault Conditions

If DTC U0140:00 or U0422:00 is present with U300A:29, diagnose the lost communication DTC first.

The ABS module, hydraulic pump and solenoid valves require an operating voltage between 10 and 17 volts. The parking brake system requires an operating voltage of 9 volts or higher. The ABS module receives this voltage from the BJB . The ABS module has 2 ground circuits. Excessive resistance or an open in one or more of these circuits, a discharged battery or a inoperative charging system results in the ABS module setting a DTC .

DTC Fault Trigger Conditions

Possible Sources

• Fuse(s)
• Wiring, terminals or connectors
• Charging system concern
• 12-volt Battery
• EBB unit (vehicles with electric boost)
• ABS module (vehicles with vacuum boost)

Visual Inspection and Pre-checks

• Make sure the vehicle battery terminals and cables are free of any corrosion and other contaminants.
• Make sure the vehicle battery terminals are tightened to their correct torque specifications.
• Make sure all EBB and ABS module fuses in the BJB BCM are OK.

Normal Operation and Fault Conditions

With the ignition ON, the HVAC control module sends messages to the GWM over the MS-CAN , The GWM relays these messages to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a HVAC control module failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the HVAC control module, refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• GWM
• HVAC control module

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

Normal Operation and Fault Conditions

The brake booster vacuum sensor receives a sensor supply voltage of 5 volts from the ABS module. The sensor is also grounded through the ABS module. The sensor uses the pressure differential between the atmosphere and the brake booster vacuum chamber to produce a return voltage signal to the ABS module between 0.2 volt and 4.9 volts. The ABS module uses other sensor inputs such as wheel speed, brake pedal and stability sensors to determine if the vehicle is stopping and at what rate of deceleration. This information is compared against the vacuum pressure sensor to determine the validity of the sensor signal and the working condition of the sensor itself.

DTC Fault Trigger Conditions

Possible Sources

• Wiring, terminals or connectors
• Brake booster vacuum leak
• Brake booster vacuum sensor
• Brake booster
• ABS module

Visual Inspection and Pre-checks

• Inspect the brake booster for vacuum leaks.
• Inspect the brake booster for any obvious signs of damage.
• Inspect the brake booster vacuum sensor harness and connector of any obvious signs of damage.
• Make sure the brake booster vacuum sensor electrical connector is free from any corrosion or other contaminants.

Normal Operation and Fault Conditions

With the ignition ON, the BCM sends messages to the GWM over the HS-CAN1 . The GWM relays these message to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a BCM failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the BCM , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• GWM
• BCM

Normal Operation and Fault Conditions

REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description (206-09 Anti-Lock Brake System (ABS) and Stability Control, Description and Operation).

Possible Sources

• Network communication concern
• IPC concern
• PCM concern
• RCM concern
• ABS module concern

• Using a diagnostic scan tool, carry out the IPC self-test.

• Using a diagnostic scan tool, carry out the IPC self-test.

• Using a diagnostic scan tool, carry out the IPC self-test.

• Using a diagnostic scan tool, carry out the IPC self-test.

Normal Operation and Fault Conditions

The ABS module may set an over-voltage DTC if the vehicle has been recently jump started, the battery has been recently charged or the battery has been discharged. The battery may become discharged due to excessive load(s) on the charging system from aftermarket accessories or if the battery has been left unattended with the accessories on.

The ABS module, hydraulic pump and solenoid valves require an operating voltage between 10 and 17 volts. The parking brake system requires an operating voltage of 9 volts or higher. The ABS module receives this voltage from the BJB . The ABS module has 2 ground circuits.

DTC Fault Trigger Conditions

Possible Sources

• Charging system concern
• EBB unit (vehicles with electric boost)
• ABS module (vehicles with vacuum boost)

Normal Operation and Fault Conditions

The ABS module incorporates a function for testing the vehicle on a dynamometer to prevent wheel speed sensor Diagnostic Trouble Codes (DTCs) from setting during testing. The PCM sends a message to the ABS module when the vehicle is setup for testing. When the ABS module receives this message it knows to ignore discrepancies between the front and rear wheel speed sensors.

The ABS module exits the test mode automatically when the PCM sends the exit message, the ignition is set to OFF, either of the non-driven wheels exceeds 20 km/h (12 mph) or a wheel speed sensor DTC is detected on any wheel speed sensor.

REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description (206-09 Anti-Lock Brake System (ABS) and Stability Control, Description and Operation).

DTC Fault Trigger Conditions

Possible Sources

• ABS module in test mode

Visual Inspection and Pre-checks

• Drive the vehicle above 20 km/h (12 mph). Stop and cycle the ignition from ON to OFF and back to ON. Carry out the ABS module self-test. If the DTC returns, retrieve and diagnose all PCM Diagnostic Trouble Codes (DTCs).

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

Normal Operation and Fault Conditions

On vacuum brake booster equipped vehicles, The ABS module uses an internal solid state switch to operate the hydraulic pump motor. The ABS module tests the hydraulic pump motor by activating it for 30 milliseconds. The ABS module monitors the voltage drop across the hydraulic pump motor while the pump motor is being activated. After 30 milliseconds have passed, the ABS module stops applying voltage to the pump motor and monitors the voltage the spinning hydraulic pump motor is generating and the voltage drop across the hydraulic pump motor solid state switch. If the monitored voltages are not within the specifications, the ABS module sets one or more Diagnostic Trouble Codes (DTCs).

On EBB equipped vehicles, the ABS module performs a check of the hydraulic system during start up and during drive cycles. The ABS module monitors the hydraulic pump motor in the EBB unit for any drops in voltage output during these tests. If a condition such as a short to ground or an open exist, the ABS module sets a DTC and modifies brake and ABS operation until the condition has been corrected.

DTC Fault Trigger Conditions

Possible Sources

• Low voltage concern - battery or charging system
• Fuses
• Wiring, terminals or connectors
• ABS module and HCU (vacuum brake booster)
• EBB unit (electric brake booster)

Normal Operation and Fault Conditions

The EBB contains several hydraulic valves, hydraulic pressure sensors, a linear actuator and a pump motor. These components work in conjunction to provide the force necessary to bring the vehicle to a stop. The ABS module monitors these components for internal faults. If a fault occurs which impacts the base braking system, the ABS module sets one or more Diagnostic Trouble Codes (DTCs) and illuminates the red brake warning indicator.

DTC Fault Trigger Conditions

Possible Sources

• Air trapped in the hydraulic system
• External brake system leak
• Internal EBB unit leak
• EBB unit internal failure

Normal Operation and Fault Conditions

With the ignition ON, the GSM sends messages to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a GSM failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the GSM , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• GSM

Normal Operation and Fault Conditions

The BCM is programmed with vehicle tire size information during the module configuration step. The BCM shares tire size information with other module over the HS-CAN1 through the GWM . When this DTC sets, the ABS module sends a message to the IPC to illuminate the ABS warning indicator.

DTC Fault Trigger Conditions

Possible Sources

• Temporary or mini-spare tire in use
• Under inflated tires
• Mismatched sized wheels and tires
• Network communication concern
• Incorrect BCM configuration

Normal Operation and Fault Conditions

The brake fluid level switch is hardwired to the ABS module, the module monitors the switch and brake fluid level. If a circuit fault or fluid loss is detected, a DTC is set.

REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description (206-09 Anti-Lock Brake System (ABS) and Stability Control, Description and Operation).

DTC Fault Trigger Conditions

Possible Sources

• Wiring, terminals or connectors
• Leak in the hydraulic system
• Brake fluid level switch
• EBB unit

• Ignition ON.

• Using a diagnostic scan tool, retrieve all ABS module Diagnostic Trouble Codes (DTCs).

• Note all ABS module Diagnostic Trouble Codes (DTCs).

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

Normal Operation and Fault Conditions

Active wheel speed sensors generate a voltage signal proportional to wheel speed which is sent to the ABS module. Each wheel speed sensor is connected to the ABS module through 2 wires and a connector at each wheel speed sensor. The 2 circuits provide both sensor power and sensor signal return. When the ignition mode is set to ON, the ABS module carries out a self-test by sending a reference voltage through the wheel speed sensors and their circuitry.

DTC Fault Trigger Conditions

Possible Sources

• Wiring, terminals or connectors
• Wheel speed sensor
• EBB unit (vehicles with electric boost)
• ABS module (vehicles with vacuum boost)

Visual Inspection and Pre-checks

• Make sure the wheel speed sensor harness is routed correctly and is undamaged.
• Make sure the wheel speed sensor electrical connector is free from any corrosion or other contaminants.

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

Normal Operation and Fault Conditions

Active wheel speed sensors generate a voltage signal proportional to wheel speed which is sent to the ABS module. Each wheel speed sensor is connected to the ABS module through 2 wires and a connector at each wheel speed sensor. The 2 circuits provide both sensor power and sensor signal return. When the ignition mode is set to ON, the ABS module carries out a self-test by sending a reference voltage through the wheel speed sensors and their circuitry.

DTC Fault Trigger Conditions

Possible Sources

• Wiring, terminals or connectors
• Wheel speed sensor
• EBB unit (vehicles with electric boost)
• ABS module (vehicles with vacuum boost)

Visual Inspection and Pre-checks

• Make sure the wheel speed sensor harness is routed correctly and is undamaged.
• Make sure the wheel speed sensor electrical connector is free from any corrosion or other contaminants.

NOTE: If equipped, MyKey allows users to configure traction control to be either always on or selectable. If a MyKey restricted key is in use with the MyKey traction control feature configured to always on, traction control cannot be disabled. An admin key must be used to enable and disable traction control.

NOTE: This test requires the use of at least 2 ignition keys (passive or IKT ) programmed to the vehicle; one admin ignition key and one restricted ignition key.

Normal Operation and Fault Conditions

The traction control switch is part of the instrument panel console switch assembly and is used to switch the traction control feature on or off. When the traction control switch is pressed, the instrument panel console switch assembly sends a ground signal to the IPC . The IPC sends a message to the GWM over the HS-CAN3 , the GWM relays this message to the ABS module over the HS-CAN2 . The ABS module continues to monitor for wheel spin but takes no action until the traction control message indicates the system has been turned on.

DTC Fault Trigger Conditions

Possible Sources

• Wiring, terminals or connectors
• Instrument panel console switch assembly
• IPC

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

• Put the ABS module in sleep mode by performing the following steps:
  • With ALL doors closed, set the ignition from ON to OFF.
  • Disconnect the diagnostic scan tool.
  • Open the door, exit the vehicle and close the door.
  • Wait a minimum of 90 seconds for the ABS module to enter sleep mode.

• Ignition ON.

• Using a diagnostic scan tool, carry out the ABS module self-test.

• Using a diagnostic scan tool, carry out the IPC self-test.

• For vehicles equipped with a keyless vehicle system,
  • place 1 of the passive keys inside the vehicle and all other passive keys at least 1 meter (3 feet) away from the vehicle.
  • press the start-stop button without pressing the brake pedal.

• For vehicles not equipped with a keyless vehicle system, turn the ignition to the ON position.

• Monitor the message center.

• Using the message center, verify the MyKey traction control setting.
  • Refer to the Owner's Literature for instructions on setting the MyKey functions.

• Using the message center, verify traction control can be enabled and disabled using the admin ignition key.
  • Refer to the Owner's Literature for instructions on enabling and disabling traction control.

• Ignition OFF.

• Disconnect IPC C220 .

• Disconnect Instrument panel console switch assembly C3010 .

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-12		Ground

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-10		C220-6

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-10		Ground

Normal Operation and Fault Conditions

The ABS module and BCM share a secret code (target identifier) when the ignition is set to ON. This code is generated during the PATS programming procedure. If either a new BCM or a new ABS module has been installed, the PATS programming procedure must be carried out.

REFER to: Perimeter Anti-Theft Alarm - System Operation and Component Description (419-01A Perimeter Anti-Theft Alarm, Description and Operation).

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• BCM programming error
• ABS module programming error

Visual Inspection and Pre-checks

• Check the vehicle repair history and determine if a new BCM or ABS module has been installed. If a new module has been installed, verify it has been programmed correctly and verify the PATS programming procedure has been carried out.

Normal Operation and Fault Conditions

The PSCM calculates steering wheel rotation speed, angle and direction of rotation and sends the information to the ABS module over the HS-CAN2 . A failure of the HS-CAN2 , the PSCM or the internal sensors causes the ABS module to set one or more Diagnostic Trouble Codes (DTCs) and the ABS warning indicator is illuminated.

REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description (206-09 Anti-Lock Brake System (ABS) and Stability Control, Description and Operation).

DTC Fault Trigger Conditions

Possible Sources

• Incorrectly mounted RCM
• Network communication concern
• Incomplete or incorrect stability control sensor calibration
• Mismatched wheels and tires
• Loose or worn suspension components
• Loose or worn steering components
• RCM
• PSCM

Normal Operation and Fault Conditions

The CCM communicates with the IPMA over a private CAN . The IPMA sends the CCM messages to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a CCM failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the CCM and IPMA , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• CCM

Normal Operation and Fault Conditions

With the ignition ON, the IPMA sends messages to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a IPMA failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the IPMA , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• IPMA

Normal Operation and Fault Conditions

These Diagnostic Trouble Codes (DTCs) are pre-set in a new ABS module and can only be cleared when the brake system has been successfully bled.

The brake system requires a certain amount of hydraulic fluid for correct operation. When the brake system is filled, the ABS module sets a PID . If the vehicle is operated and the ABS module detects this PID has not been set, a DTC is set.

DTC Fault Trigger Conditions

Possible Sources

• Brake system has not been bled

• Ignition ON.

• Using a diagnostic scan tool, carry out the ABS module self-test.

Normal Operation and Fault Conditions

The hill descent control switch is part of the instrument panel console switch assembly and is hardwired to the IPC . When the hill descent control switch is pressed, the IPC receives a ground signal and sends a message to the GWM over the MS-CAN . The GWM relays the message to the ABS module over the HS-CAN2 . If the ABS module does not receive any messages within a certain time frame (usually less than 1 second) or if the message contains invalid information, the ABS module sets a DTC .

Possible Sources

• Wiring, terminals or connectors.
• Instrument panel switch assembly
• Network concern
• IPC

• Ignition ON.

• Using a diagnostic scan tool, carry out the IPC self-test.

• Retrieve and record all IPC Diagnostic Trouble Codes (DTCs).

• Review the results from the previous step.

• Disconnect IPC C220 .

• Disconnect Instrument panel console switch assembly C3010 .

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-12		Ground

• Ignition ON.

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-2		Ground

• Ignition OFF.

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-2		Ground

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-2		C220-7

Normal Operation and Fault Conditions

The ABS module monitors all base brake, anti-lock brake, traction control and stability control functions and features. If a system error occurs which could cause irreparable damage to the system, the ABS module disables the EBB unit. The base brake system still functions, but there is no brake boost assist. This can also occur if the EBB unit loses power or ground.

System over-voltage combined with other specific circumstances may cause the EBB unit to provide excessive brake assist or a "touchy" pedal, where the brakes apply heavily with a light application of the brake pedal.

In either of these cases, no brake assist or too much brake assist, the ABS module sets Diagnostic Trouble Codes (DTCs) indicating possible concerns.

Possible Sources

• Diagnostic Trouble Codes (DTCs) preset in the ABS module

Visual Inspection and Pre-checks

• RETRIEVE and DIAGNOSE all ABS module Diagnostic Trouble Codes (DTCs)

Normal Operation and Fault Conditions

The ABS module uses several sensors (wheel speed, steering wheel rotation, stability control) to determine if ABS or stability control intervention is required. Accurate sensor readings rely on the vehicle being in good operational condition with as few mechanical and electrical concerns as possible. In addition, the wheels and tires must be within vehicle manufacturer's specifications as described on the VC label and the base brake system and parking brake system must be in good operational condition. If one or more of these items or systems are in need or repair or are not working at full capacity, the ABS or stability control system may activate when the driving condition does not warrant activation.

Possible Sources

• Wheels
• Tires
• Suspension components
• Parking brake dragging
• PSCM
• RCM

Normal Operation and Fault Conditions

The ABS module continually monitors the brake system for potential system concerns. During module wake up, several items are monitored and certain operations are expected to be performed. If one or more of these do not occur as expected, the ABS module sets a DTC and requests the illumination of the ABS warning indicator.

REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description (206-09 Anti-Lock Brake System (ABS) and Stability Control, Description and Operation).

DTC Fault Trigger Conditions

Possible Sources

• Other Diagnostic Trouble Codes (DTCs) present in the ABS module
• EBB unit

Normal Operation and Fault Conditions

The ABS module carries out self tests during operation, the module also monitors various inputs and compares the values to what is expected. If the values received are out of range, are not what is expected, or if any of the self tests fail, the ABS module sets a DTC .

DTC Fault Trigger Conditions

Possible Sources

• Incorrect sensor input
• Stuck valve
• EBB unit (electric boosted vehicles)
• ABS module (vacuum boosted vehicles)

Normal Operation and Fault Conditions

During new module installation, configuration files are loaded into the new module being replaced. If a discrepancy is detected between the modules or an incomplete programming procedure is carried out, a DTC is set.

DTC Fault Trigger Conditions

Possible Sources

• Incomplete programming procedure
• Improper programming procedure
• EBB unit (vehicles with electric boost)
• ABS module (vehicles with vacuum boost)

Normal Operation and Fault Conditions

The selectable drive mode switch is part of the instrument panel console switch assembly and is hardwired to the HVAC control module. When the drive mode switch is pressed, the HVAC control module receives a ground signal and sends a message to the GWM over the MS-CAN . The GWM relays the message to the ABS module over the HS-CAN2 . If the ABS module does not receive any messages within a certain time frame (usually less than 1 second) or if the message contains invalid information, the ABS module sets a DTC .

DTC Fault Trigger Conditions

Possible Sources

• Wiring, terminals or connectors.
• Instrument panel switch assembly
• Network concern
• HVAC control module

• Ignition ON.

• Using a diagnostic scan tool, carry out the HVAC control module self-test.

• Retrieve and record all HVAC control module Diagnostic Trouble Codes (DTCs).

• Review the results from the previous step.

• Ignition OFF.

• Disconnect HVAC Module C228A .

• Disconnect Instrument panel console switch assembly C3010 .

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-12		Ground

• Ignition ON.

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-1		Ground

• Ignition OFF.

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-1		Ground

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-1		C228A-14

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

Normal Operation and Fault Conditions

The wheel speed sensor uses the tone ring to generate a square wave signal proportional to wheel speed which is sent to the ABS module. The front wheel bearing, rear axle shafts, tone rings and wheel speed sensors must be undamaged and free from any contamination to produce a clean signal for use by the ABS module. Also, all 4 tires and wheels must be of the same manufacturer recommended size for the wheel speed sensor to generate an accurate wheel speed signal.

DTC Fault Trigger Conditions

Possible Sources

• Tire Pressure
• Incorrect or mismatched tire
• Wheel speed sensor encoder contamination
• Wiring, terminals or connectors
• Wheel bearing
• Wheel speed sensor encoder ring
• Wheel speed sensor
• EBB unit (vehicles with electric boost)
• ABS module (vehicles with vacuum boost)

Normal Operation and Fault Conditions

The BPP switch is also known as the stoplamp switch.

The ABS module receives BPP switch input from the PCM through the GWM over the HS-CAN . The ABS module compares this information against brake fluid pressure sensor input and brake pedal input to determine if the BPP switch input is valid. An incorrectly installed BPP switch can cause a signal plausibility concern. An implausible signal can also be created if a driver is resting one foot on the brake pedal while using the other foot to press the accelerator.

REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description (206-09 Anti-Lock Brake System (ABS) and Stability Control, Description and Operation).

DTC Fault Trigger Conditions

Possible Sources

• Pressing both pedals (brake and accelerator) at the same time
• Wiring, terminals or connectors
• Brake pedal (stoplamp) switch
• Network communication concern
• .ABS module (vacuum booster equipped vehicles)
• EBB unit (electric booster equipped vehicles)

Normal Operation and Fault Conditions

The ABS module uses information from the wheel speed sensors, RCM and PSCM to determine when stability control intervention is necessary to help stabilize the vehicle. The ABS module uses the EBB unit (electric boosted vehicles) or the HCU (vacuum boosted vehicles) to modulate the brake fluid pressure to the brake calipers and continues to monitor the sensor and module input until the instability event has been corrected. Once the sensors and modules indicate the instability event has been corrected, the ABS module deactivates the EBB unit (electric boosted vehicles) or the HCU (vacuum boosted vehicles). Under inflated tires, wheels and tires that do not match VC label specifications, suspension and steering damage, and one or more sensor failures contribute to the ABS module setting this DTC .

DTC Fault Trigger Conditions

Possible Sources

• Tire pressure
• Wiring, terminals or connectors
• Chassis damage
• Steering damage or alignment
• Wheel speed sensor
• RCM
• PSCM

Normal Operation and Fault Conditions

With the ignition ON, the PSCM sends messages to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a PSCM failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the PSCM , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• GWM
• PSCM

Normal Operation and Fault Conditions

When the ignition is set to ON, the ABS module and the BCM share VIN information through the GWM over the HS-CAN1 and FD-CAN .

When a new EBB unit or ABS module is installed, the ABS module must be programmed with the vehicle information. REFER to: Module Configuration - System Operation and Component Description (418-01 Module Configuration, Description and Operation).

DTC Fault Trigger Conditions

Possible Sources

• BCM configuration
• ABS module configuration

Normal Operation and Fault Conditions

With the ignition ON, the diagnostic scan tool communicates with the ABS module over the HS-CAN2 . Communications can be interrupted by a wiring condition such as a short to ground, a short to voltage or an open circuit; module failure may also be a cause of no communication.

Refer to Section 418-00 to diagnose the no communication concern. REFER to: Communications Network (418-00 Module Communications Network, Diagnosis and Testing).

Possible Sources

• Fuse
• Wiring, terminals or connectors
• EBB unit (electric boosted vehicles)
• ABS module (vacuum boosted vehicles)

Normal Operation and Fault Conditions

The ABS module uses a vacuum sensor to monitor the brake booster vacuum.

On 2.0L EcoBoost engines, a camshaft driven vacuum pump supplies the vacuum to the brake booster. The vacuum pump is expected to produce at least 600 mBar (18 In-Hg). A leak in a vacuum hose, brake booster or one of the seals on the brake booster or vacuum pump prevents the vacuum pump from achieving the required amount of vacuum. Damage or an internal failure also prevents the vacuum pump from operating at peak capacity.

On all other engines, the engine supplies the vacuum to the brake booster through a series of hoses and tubes. A leak in a vacuum hose, tube, brake booster or one of the seals on the brake booster or vacuum pump prevents the brake booster from achieving the required amount of vacuum.

DTC Fault Trigger Conditions

Possible Sources

• Vacuum leak
• Vacuum hose obstruction
• Vacuum pump (if equipped)
• Brake booster

Normal Operation and Fault Conditions

With the ignition ON, the PCM sends messages to the GWM over the HS-CAN1 . The GWM relays these message to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a PCM failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the PCM , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

The TCM is an internal component of the PCM .

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• PCM

Normal Operation and Fault Conditions

With the ignition in RUN, the ABS module continuously monitors the base brake system, the ABS , and the stability control system. If there is a concern present in one of the systems, the ABS module sets a DTC and sends a message to the GWM over the FD-CAN , the GWM relays this message to the IPC . Once the message is received, the IPC illuminates the appropriate warning indicator.

The IPC also illuminates the warning indicators as part of a self test when the ignition is set to RUN or ACC. REFER to: Instrument Panel Cluster (IPC) - System Operation and Component Description (413-01 Instrumentation, Message Center and Warning Chimes, Description and Operation).

Possible Sources

• Diagnostic Trouble Codes (DTCs) present in the ABS module
• Low brake fluid
• Brake fluid level sensor
• ABS or stability control concern
• IPC concern

Visual Inspection and Pre-checks

• Check for ABS module Diagnostic Trouble Codes (DTCs), if there are no Diagnostic Trouble Codes (DTCs) present, refer to Section 413-01 to diagnose the IPC warning indicators.

Normal Operation and Fault Conditions

With the ignition ON, the GWM sends messages to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a GWM failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the GWM , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• GWM

Normal Operation and Fault Conditions

The ABS module carries out a self-check each time the ignition mode is changed to RUN. If the ABS module detects a fault, one or more Diagnostic Trouble Codes (DTCs) set. REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description (206-09 Anti-Lock Brake System (ABS) and Stability Control, Description and Operation).

DTC Fault Trigger Conditions

Possible Sources

• Wheel speed sensor input concern
• Wheel speed sensor
• EBB unit ( EBB vehicles
• ABS module (vacuum brake booster vehicles)

Normal Operation and Fault Conditions

The ABS module monitors various inputs and compares the values to what should be expected. If the values received are out of range or not what should be expected, the ABS module sets a DTC .

DTC Fault Trigger Conditions

Possible Sources

• Incorrect sensor input
• Air trapped in the hydraulic system
• EBB unit (electric boosted vehicles)
• ABS module and HCU assembly (vacuum boosted vehicles)

Normal Operation and Fault Conditions

The ABS module monitors various inputs and compares the values to what should be expected. If the values received are out of range or not what is expected, the ABS module sets a DTC . When a new ABS module or RCM is installed, the stability control sensors in the RCM must be initialized. This is accomplished using a diagnostic scan tool to run the ABS Calibration routine.

DTC Fault Trigger Conditions

Possible Sources

• ABS Calibration routine not carried out
• RCM concern
• EBB unit (electric boosted vehicles)
• ABS module (vacuum boosted vehicles)

Normal Operation and Fault Conditions

Vehicles equipped with EPB are also equipped with an auto hold feature. This feature must be enabled by the driver by pressing the auto hold switch once the driver seatbelt is buckled and the driver door is closed.

The auto hold switch is part of the instrument panel console switch assembly and is hardwired to the HVAC control module. Pressing the auto hold switch enables the auto hold feature, but does not activate auto hold.

When the switch is pressed, the HVAC control module receives a ground signal from the switch. The HVAC control module sends a message to the GWM over the MS-CAN . The GWM relays the message to the ABS module over the HS-CAN2 indicating the system has been enabled. The ABS module then waits for messages from the RCM and BCM as well as ABS sensor information to indicate the auto hold feature can be activated. Once all criteria has been met, the ABS module activates the auto hold feature.

In the case of a system error, the instrument cluster displays messages and icons.

Possible Sources

• Wiring, terminals or connectors
• Network communication concern
• Instrument panel console switch assembly
• RCM concern
• BCM concern
• HVAC module concern

• Ignition ON.

• Using a diagnostic scan tool, carry out the Network test.

• Using a diagnostic scan tool, carry out the following module self-tests:
  • BCM
  • HVAC control module
  • RCM

• Disconnect HVAC C228A.

• Disconnect Instrument panel console switch assembly C3010.

• Ignition ON.

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-3		Ground

• Ignition OFF.

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-3		Ground

• Measure:
  Click to display connectors
  

  Positive Lead	Measurement / Action	Negative Lead
  C3010-3		C228A-5

Normal Operation and Fault Conditions

With the ignition ON, the AWD module sends messages to the GWM over the HS-CAN1 . The GWM relays these message to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a AWD module failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the AWD module refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• AWD module

Normal Operation and Fault Conditions

The CCM communicates with the IPMA over a private CAN . The IPMA sends the CCM messages to the GWM over the HS-CAN2 . The GWM relays these messages to the ABS module over the FD-CAN . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a CCM failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the CCM and IPMA , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• CCM

Normal Operation and Fault Conditions

With the ignition ON, the IPC sends messages to the GWM over the HS-CAN3 . The GWM relays these messages to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a IPC failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the IPC , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• GWM
• IPC

Normal Operation and Fault Conditions

With the ignition ON, the FCIM sends messages to the GWM over the MS-CAN , The GWM relays these messages to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a FCIM failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the FCIM , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

The hill descent control switch is part of the FCIM . When the hill descent control switch is touched, the FCIM sends a message to the GWM over the HS-CAN3 . The GWM relays the message to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within a certain time frame (usually less than 1 second) or if the message contains invalid information, the ABS module sets a DTC .

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• GWM
• FCIM

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

Normal Operation and Fault Conditions

The EBB unit uses a motor to pressurize the brake system and to operate the ABS , ESC , RSC and other stability control features. The ABS module monitors the motor performance and sets a DTC when a motor fault is detected.

DTC Fault Trigger Conditions

Possible Sources

• Fuses
• Wiring, terminals or connectors
• EBB unit

NOTE: The HEV - PCM may also be known as the SOBDMC .

Normal Operation and Fault Conditions

With the ignition ON, the HEV - PCM sends messages to the GWM over the HS-CAN1 . The GWM relays these message to the ABS module over the HS-CAN2 . If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC . This can be due to a HEV - PCM failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the HEV - PCM , refer to the Network Message Chart in Section 206-09, Description and Operation in the Workshop Manual.

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• HEV - PCM

Normal Operation and Fault Conditions

The ABS module receives vehicle yaw rate, lateral acceleration, longitudinal acceleration and roll rate from RCM over the HS-CAN2 , through the GWM . The yaw rate sensor, lateral accelerometer, longitudinal accelerometer and roll rate sensor are all contained in the RCM . A failure of the HS-CAN2 , an internal failure of the RCM or the internal sensors causes the ABS module to set one or more Diagnostic Trouble Codes (DTCs).

DTC Fault Trigger Conditions

Possible Sources

• Network communication concern
• Incorrectly installed RCM
• RCM