Pinpoint Test K : DTC U0121
WARNING: This page is about a different variant/trim than selected.
- K1 CHECK THE COMMUNICATION NETWORK
- Ignition ON.
- Using the diagnostic scan tool, perform the network test.
Does the ABS module pass the network test?
Yes For GSM, GO to K2 For TRCM, GO to K4 No To diagnose the module does not respond to the scan tool, REFER to: Communications Network . - K2 CHECK FOR GSM (GEAR SHIFT MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
- Clear all DTCs.
- Using the diagnostic scan tool, perform the GSM self-test.
Is DTC U0121 present?
Yes GO to K3 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. - K3 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE GSM (GEAR SHIFT MODULE) SELF-TEST
- Check for DTCs from the self-test.
Are any GSM DTCs present?
Yes REFER to the GSM DTC chart and diagnose those DTCs first. No GO to K6 - K4 CHECK FOR TRCM (TRANSMISSION RANGE CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
- Clear all DTCs.
- Using the diagnostic scan tool, perform the TRCM self-test.
Is DTC U0121 present?
Yes GO to K5 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. - K5 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE TRCM (TRANSMISSION RANGE CONTROL MODULE) SELF-TEST
- Check for DTCs from the self-test.
Are any TRCM DTCs present?
Yes REFER to the TRCM DTC chart and diagnose those DTCs first. No GO to K6 - K6 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE ABS (ANTI-LOCK BRAKE SYSTEM) SELF-TEST
- Check for DTCs from the self-test.
Is DTC U3000:49 present?
Yes REFER to: Anti-Lock Brake System (ABS) and Stability Control . No GO to K7 - K7 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) U0121 SET IN OTHER MODULES
- Using the diagnostic scan tool, perform the self-test for all modules.
- Retrieve the DTCs from all modules.
Is DTC U0121 present in the ABS or IPC modules?
Yes CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, discontinue this test and follow TSB instructions. If no TSBs address this concern, Refer to ABS GUIDED ROUTINE TESTING No If the reporting module is the GSM, INSTALL a new GSM. REFER to: Gearshift Module (GSM) . If the reporting module is the TRCM, INSTALL a new TRCM. REFER to: Transmission Range Control Module (TRCM) .