DTC U0401-68 (VSA Control Unit)

ElectronicCircuitSchematics-buttonADInfo-button DTC Advanced Diagnostics: VSA related DTCs SystemDescription-button OverviewDTC U0401-68  : (ECM Failure)

DTCs (VSA)

1. Problem verification

   -1. Turn the vehicle to the ON mode.

   -2. Clear the DTC with the HDS.

   -3. Turn the vehicle to the OFF (LOCK) mode, then start the engine.

   -4. Check for DTCs with the HDS.

   DTC Description	DTC
   U0401-68 (ECM Failure)

   Is DTC U0401-68 indicated?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting .

2. PGM-FI DTCs check

   -1. Check for PGM-FI DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC

   Are any DTCs indicated?

   YES 

   Go to indicated DTCs troubleshooting. After all PGM-FI DTC's have been repaired, return to VSA and clear this code.

   NO 

   Go to step 3.

3. PCM check

   -1. Substitute a known-good PCM .

   -2. Clear the DTC with the HDS.

   -3. Turn the vehicle to the OFF (LOCK) mode, then start the engine.

   -4. Check for DTCs with the HDS.

   DTC Description	DTC
   U0401-68 (ECM Failure)

   Is DTC U0401-68 indicated?

   YES 

   Check for loose terminals and poor connections in the VSA modulator-control unit 38P connector. If they are OK, replace the VSA modulator-control unit .

   NO 

   If the PCM was substituted, replace the original PCM .