Diagnostic Test
- CHECK FOR DTCS U0001-CAN C BUS DTC or U0121-LOST COMMUNICATION WITH ANTI-LOCK BRAKE MODULE
- With the scan tool, check DTCs.
Is DTC U0001-CAN C BUS DTC or U0121-LOST COMMUNICATION WITH ANTI-LOCK BRAKE MODULE set?
Yes
- Refer to the DTC INDEX article. Perform the diagnostic procedure for U0001-CAN C BUS DTC first if it is present.
- Perform the NAG1 TRANSMISSION VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 2
- With the scan tool, check DTCs.
- CHECK FOR ABS DTCS
- With the scan tool, read ABS DTCs.
Are there any ABS DTCs present?
Yes
- Refer to the DTC INDEX article and perform the appropriate diagnostic procedure.
- Perform the NAG1 TRANSMISSION VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the TCM in accordance with the Service Information.
- Perform the NAG1 TRANSMISSION VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- With the scan tool, read ABS DTCs.