Pinpoint Test AP: Abs Module Communication Concern With The TCU
- Normal Operation and Fault Conditions
With the ignition ON, the TCU sends messages to the GWM over the FD-CAN2, the GWM relays the messages to the ABS module over the FD-CAN1. If the ABS module does not receive these messages within a certain time frame (usually less than 1 second), the ABS module sets a DTC. For information on the messages sent to the ABS module by the TCU, 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 U0198:87 Lost Communication With Telematic Control Module 'A': Missing Message This DTC sets when the ABS module does not receive any messages from the TCU within the allowed time. Possible Causes
- Network communication concern
- GWM
- TCU
Visual Inspection and Pre-checks
- Make sure the vehicle battery state of charge is at least 80%
- Make sure the vehicle battery voltage is at least 11 VDC
- AP1 CHECK THE TCU (TELEMATIC CONTROL UNIT MODULE) COMMUNICATION
- Ignition ON.
- Using a diagnostic scan tool, carry out the TCU self-test. Only available in the service information
Does the TCU communicate with the diagnostic scan tool and return DTCs '
Yes RETRIEVE and RECORD all TCUDTCs. REFER to: Information and Entertainment System . If there are no DTCs in the TCU, GO to AP3 No GO to AP2. - AP2 CHECK THE GWM (GATEWAY MODULE A) COMMUNICATION
- Using a diagnostic scan tool, carry out the GWM self-test. Only available in the service information
Does the GWM communicate with the diagnostic scan tool and return DTCs '
Yes RETRIEVE and RECORD all GWMDTCs. REFER to: Controller Area Network (CAN) Module Communications Network .
No DIAGNOSE the scan tool does not communicate with the GWM. REFER to: Controller Area Network (CAN) Module Communications Network . - AP3 RECHECK THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE FOR THE LOST COMMUNICATION DTC (DIAGNOSTIC TROUBLE CODE)
- Using a diagnostic scan tool, clear the ABS module Diagnostic Trouble Codes (DTCs). Only available in the service information
- Ignition OFF.
- Ignition ON.
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NOTE: When retrieving DTCs, ignore all historical or continuous memory DTCs.
Using a diagnostic scan tool, carry out the ABS module self-test. Only available in the service information
Are any of the DTCs listed in the DTC Fault Trigger Conditions table present and active in the ABS module?
Yes GO to AP4. 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 - AP4 REVIEW THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE SELF-TEST FOR VOLTAGE-REALTED DTCS
- Review the results from the ABS module self-test.
Is DTC U3003:16 or U3003:17 present?
Yes For DTC U3003:16, GO to Pinpoint Test A For DTC U3003:17, GO to Pinpoint Test F No GO to AP5. - AP5 CHECK FOR GWM (GATEWAY MODULE A) DTCS
- Using a diagnostic scan tool, carry out the GWM self-test. Only available in the service information
Are any DTCs present and active in the GWM '
Yes RETRIEVE and RECORD all GWMDTCs. REFER to: Controller Area Network (CAN) Module Communications Network .
No GO to AP6. - AP6 CHECK FOR TCU (TELEMATIC CONTROL UNIT MODULE) DTCS
- Using a diagnostic scan tool, carry out the TCU self-test. Only available in the service information
Are any DTCs present and active in the TCU '
Yes RETRIEVE and RECORD all TCUDTCs. REFER to: Information and Entertainment System . No GO to AP7. - AP7 CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERN
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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 TCU 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 AP8. No The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration. -
- AP8 CHECK FOR COMMUNICATION DTCS IN OTHER MODULES
- Ignition ON.
-
NOTE: When retrieving DTCs, ignore all historical or continuous memory DTCs.
Using a diagnostic scan tool, carry out a Network Test.
Is any DTC from the Fault Trigger Conditions Table set in 1 or more modules in addition to the ABS module?
Yes GO to AP9. No GO to AP10 - AP9 VERIFY TCU (TELEMATIC CONTROL UNIT MODULE) OPERATION
- Ignition OFF.
- Disconnect TCU C4803A.
- Disconnect GWM C2451.
- Disconnect ABS Module C135.
- 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 TCU C4803A Make sure the connector seats and latches correctly.
- Connect GWM C2451 Make sure the connector seats and latches correctly.
- Connect ABS Module C135 Make sure the connector seats and latches correctly.
- Operate the system and verify 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 TCU C4803A. REFER to: Telematics Control Unit (TCU) Module . 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. - AP10 VERIFY ABS (ANTI-LOCK BRAKE SYSTEM) OPERATION
- Ignition OFF.
- Disconnect TCU C4803A.
- Disconnect GWM C2451.
- Disconnect ABS Module C135.
- 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 TCU C4803A Make sure the connector seats and latches correctly.
- Connect GWM C2451 Make sure the connector seats and latches correctly.
- Connect ABS Module C135 Make sure the connector seats and latches correctly.
- Operate the system and verify 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 unit. 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.