Pinpoint Test J : U0121, U0129, U0415
- Refer to Module Communications Network
for schematic and connector information.
Normal Operation and Fault Conditions
When a network message is suspected as missing or confirmed by a missing message DTC (U-code), its important to look for other conditions that may also be present in additional modules throughout the vehicle. Once a DTC sets in the TCM, it may be helpful to review the complete message list available in the Master DTC Chart and see what other modules also rely on the same message and run the self-test for those modules. If the message is missing from other modules, the same DTC may also set in those modules. Confirmation of missing messages common to multiple modules may indicate that the originating module is the source of the concern or the communication network may be experiencing some problems.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition TCM U0121:00 Lost Communication With Anti-Lock Brake System (ABS) Control Module "A": No Sub Type Information Lost communication with ABS module but the TCM is receiving messages from other modules. TCM U0129:00 Lost Communication with Brake System Control Module "A": No Sub Type Information Lost communication with ABS module but the TCM is receiving messages from other modules. TCM U0415:00 Invalid Data Received from Anti-Lock Brake System (ABS) Control Module "A": No Sub Type Information Receiving CAN messages from the ABS but the ABS is indicating failures of certain key signals. Possible Sources
- Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
- Fuse
- Network
- J1 READ AND RECORD ALL DTCS
- Using the diagnostic scan tool, retrieve all DTCs.
Are DTCs U0121, U0129 and/or U0415 present?
Yes GO to J2 No The system is operating normally at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - J2 CHECK FOR CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODES (CMDTCS)
- Using the diagnostic scan tool, retrieve all CMDTCs.
Did DTC U3003:16 or U3003:17 set?
Yes For U3003:16 and/or U3003:17 REFER to: Anti-Lock Brake System (ABS) And Stability Control . No GO to J3 - J3 CHECK THE COMMUNICATION NETWORK
- Ignition ON.
- Carry out the network test.
Does the ABS module pass the network test?
Yes GO to J4 No REFER to: Anti-Lock Brake System (ABS) And Stability Control . - J4 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) U0121, U0129 AND/OR U0415 SET IN OTHER MODULES
- Using the diagnostic scan tool, retrieve all CMDTCs.
Are DTCs U0121, U0129 and/or U0415 present in other modules?
Yes INSTALL a new ABS module. REFER to: Anti-Lock Brake System (ABS) Module . No The system is operating normally at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.