Pinpoint Test Ai: Abs (Anti-Lock Brake System) Module Communication Concern With Pcm (Powertrain Control Module)

Refer to Module Communications Network for schematic and connector information.

Normal Operation and Fault Conditions

With the ignition ON, the PCM sends messages to the ABS module over the CAN. If the ABS module does not receive these messages within the specified time frame, the ABS module sets Diagnostic Trouble Codes (DTCs). This can be due to a PCM failure, a circuit failure on the CAN or an excessive load on the network. For information on the messages sent to the ABS module by the PCM, REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
ABS U0100:00	Lost Communication With ECM/PCM 'A': No Sub Type Information	Sets when the ABS module does not receive any messages from the PCM. This can be due to a PCM failure, a circuit failure on the HS-CAN or an excessive load on the network.
ABS U0100:82	Lost Communication With ECM/PCM 'A': Alive/Sequence Counter Incorrect/Not Updated	Sets when the ABS module receives the wheel torque data with unchanged counters from the PCM. This can be due to a PCM failure, a circuit failure on the CAN or an excessive load on the network.
ABS U0100:83	Lost Communication With ECM/PCM 'A': Value Of Signal Protection Calculation Incorrect	Sets when the ABS module receives the wheel torque data with invalid data from the PCM. This can be due to a PCM failure, a circuit failure on the CAN or an excessive load on the network.
ABS U0100:87	Lost Communication With ECM/PCM 'A': Missing Message	Sets when the ABS module does not receive any messages from the PCM. This can be due to a PCM failure, a circuit failure on the CAN or an excessive load on the network.
ABS U0401:81	Invalid Data Received from ECM/PCM A: Invalid Serial Data Received	Sets if the ABS module receives invalid data in the brake pedal, accelerator pedal or clutch pedal position messages from the PCM. This can be due to a PCM failure, a circuit failure on the CAN or an excessive load on the network.
ABS U0401:83	Invalid Data Received from ECM/PCM A: Value Of Signal Protection Calculation Incorrect	Sets when the ABS module receives the wheel torque data with incorrect checksum data from the PCM. This can be due to a PCM failure, a circuit failure on the CAN or an excessive load on the network.
ABS U0401:82	Invalid Data Received from ECM/PCM A: Alive/Sequence Counter Incorrect/Not Updated	Sets if the ABS module receives invalid data in the driven wheel torque message or in the reverse gear message from the PCM. This can be due to a PCM failure, a circuit failure on the CAN or an excessive load on the network.
ABS U0401:86	Invalid Data Received from ECM/PCM A: Signal Invalid	Sets if the ABS module is configured for one type of selectable drive mode switch and the ABS module receives a message for a different type of selectable drive mode switch.
ABS U0402:00	Invalid Data Received from TCM: No Sub Type Information	sets if the ABS module is configured for one type of selectable drive mode switch and the ABS module receives a message for a different type of selectable drive mode switch.

Possible Causes

Network communication concern
PCM
GWM

AI1 CHECK THE PCM (POWERTRAIN CONTROL MODULE) COMMUNICATION
- Ignition ON.
- Using a diagnostic scan tool, carry out the Network Test.
- Using a diagnostic scan tool, retrieve the Diagnostic Trouble Codes (DTCs) from the vehicle. NOTE: Diagnostic Trouble Codes (DTCs) may be displayed from previous diagnostic actions.
Does the PCM pass the Network Test?

Yes GO to AI2

No DIAGNOSE the PCM does not communicate with the diagnostic scan tool. REFER to: COMMUNICATIONS NETWORK .

AI2 CHECK FOR PCM (POWERTRAIN CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Using a diagnostic scan tool, carry out the PCM self-test.
Are any PCM Diagnostic Trouble Codes (DTCs) present?

Yes DIAGNOSE the PCM DTC s.

No GO to AI3

AI3 CHECK THE ABS (ANTI-LOCK BRAKE SYSTEM) FOR THE LOST COMMUNICATION DIAGNOSTIC TROUBLE CODE (DTC)

NOTE: When retrieving Diagnostic Trouble Codes (DTCs), ignore all historical or CMDTC s.

Using a diagnostic scan tool, clear the ABS module DTC s.

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 self-test

Are any DTCs from the DTC Fault Trigger Conditions Table present and active in the ABS module?

Yes

GO to AI4

No	The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition

AI4 REVIEW THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE SELF-TEST FOR VOLTAGE-RELATED DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, review the recorded DTCs from the ABS self-test.
Are any voltage Diagnostic Trouble Codes (DTCs) present in the ABS module?

Yes REFER to the DIAGNOSTIC TROUBLE CODE (DTC) CHART .

No GO to AI5

AI5 CHECK FOR PCM (POWERTRAIN CONTROL MODULE) DTC (DIAGNOSTIC TROUBLE CODES)
- Using a diagnostic scan tool, carry out the PCM self-test.
Are any Diagnostic Trouble Codes (DTCs) present?

Yes DIAGNOSE the PCM DTC s.

No GO to AI6

AI6 CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERN

NOTE: If new modules were installed prior to the DTC being set, the module configuration can be incorrectly set during the PMI or the PMI may not have been carried out.

Check the vehicle service history for recent service actions related to the PCM or the ABS module. If recent service history is found:
- Verify the correct replacement module was installed. HVBOM may be used to verify correct part fitment.
- Verify the configuration of replacement module was correct. Re-configure the module using as-built data if prior configuration is suspect.
- Verify the module was not obtained from a like vehicle and installed into customer vehicle. Return the swapped module to source vehicle and obtain new replacement module.

Operate the system and determine if the observable symptom is still present.

Is the observable symptom still present?

Yes

GO to AI7

No	The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

AI7 CHECK FOR COMMUNICATION DTC (DIAGNOSTIC TROUBLE CODES) SET IN OTHER MODULES
- Using a diagnostic scan tool, retrieve the DTCs from the vehicle. NOTE: DTCs may be displayed from previous diagnostic actions.
Is any DTC from the fault trigger table set in 1 or more modules in addition to the ABS module?

Yes GO to AI8

No GO to AI9

AI8 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) MODULE OPERATION

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.

Disconnect ABS module, if not previously disconnected.

Disconnect PCM, if not previously disconnected.

Disconnect GWM, if not previously disconnected.

Using a good light source, INSPECT all Disconnected electrical connectors for the following:
- Corrosion - INSTALL new connector or terminal and clean the module pins
- Damaged or bent pins - INSTALL new terminals or pins
- Pushed-out pins - INSTALL new pins as necessary
- Spread terminals - INSTALL new terminals as necessary

Connect GWM.

Connect PCM.

Connect ABS module.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes

For Hybrid Electric Vehicle:
CHECK OASIS for any service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service article exists for this concern, INSTALL a new SOBDM
For all others: CHECK OASIS for any service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service article exists for this concern, INSTALL a new PCM. REFER to: Powertrain Control Module (PCM) .

No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.

AI9 CHECK FOR CORRECT ABS (ANTI-LOCK BRAKE SYSTEM) MODULE OPERATION

Ignition OFF.

Disconnect ABS module connector C135, if not previously disconnected.

Using a good light source, INSPECT all Disconnected electrical connectors for the following:
- Corrosion - INSTALL new connector or terminal and clean the module pins
- Damaged or bent pins - INSTALL new terminals or pins
- Pushed-out pins - INSTALL new pins as necessary
- Spread terminals - INSTALL new terminals as necessary

Connect the ABS module connector. Make sure it seats and latches correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new EBB. REFER to: Electric Brake Booster (EBB) .

No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.