Pinpoint Test O: U0100:00
- Normal Operation and Fault Conditions
REFER to: Exterior Lighting - Overview . REFER to: Exterior Lighting - System Operation and Component Description .
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition HCM U0100:00 Lost Communication With ECM/PCM "A": No Sub Type Information A continuous memory and on-demand DTC that sets in continuous memory in the HCM if data messages received from the PCM are missing for 5 seconds or longer. Possible Sources
- Communication concern
- Battery voltage concern
- PCM
- HCM
- O1 VERIFY THE SCAN TOOL COMMUNICATES WITH THE PCM (POWERTRAIN CONTROL MODULE)
- Ignition ON.
- Connect the scan tool.
- Using the diagnostic scan tool, verify that a vehicle session can be established.
Can a vehicle session be established?
Yes GO to O2 No - O2 CHECK THE HEADLAMP HCM (HEADLAMP CONTROL MODULE) CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODES (CMDTCS)
- Using a diagnostic scan tool, perform the HCM self-test.
- Clear the Diagnostic Trouble Codes (DTCs).
- Wait 10 seconds.
- Repeat the HCM self-test.
Is DTC U0100:00 set again?
Yes GO to O3 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. - O3 PERFORM THE PCM (POWERTRAIN CONTROL MODULE) SELF-TEST
- Using a diagnostic scan tool, perform the PCMKOEO and KOER self-test.
Are any DTCDiagnostic Trouble Codes (DTCs) recorded?
Yes Diagnose the PCM Diagnostic Trouble Codes (DTCs). REFER to: the appropriate Electronic Engine Controls service information . No GO to O4 - O4 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) U0100:00
- Using a diagnostic scan tool, clear all Diagnostic Trouble Codes (DTCs).
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Using a diagnostic scan tool, perform the continuous memory self-test.
- Retrieve the Continuous Memory Diagnostic Trouble Codes (CMDTCs) from all modules.
Is DTC U0100:00 set in the ABS module?
Yes INSTALL a new PCM. REFER to: Powertrain Control Module (PCM) - MI4, Removal and Installation). REFER to: Powertrain Control Module (PCM) , Removal and Installation). No INSTALL a new HCM. REFER to: Headlamp Control Module (HCM) .