Inspection steps

CAUTION: Perform all of steps to Step 9 in "HOW TO TROUBLESHOOT " before performing this steps.

DTC check
1. Check the displayed DTC.
  Criteria: DTCs other than U**** are not output
  
  NO: Perform the diagnosis according to the DTC.
  
  YES: Go to next step
DTC check
1. Check the displayed DTC.
  Criteria: No DTC indicating bus off or missing data is output
  
  NO: Perform the diagnosis according to the DTC.
  
  YES: Go to next step
DTC check
1. Check the displayed DTC.
  Criteria: U0401 is output
  
  NO: Go to "How to simulate trouble phenomenon" (Refer to PROCEDURES FOR MALFUNCTION PHENOMENON SIMULATION )
  
  YES: Go to next step
DTC check
1. Turn the ignition switch to OFF.
2. Disconnect the engine control computer connector.
3. Reconnect the disconnected connector and turn the ignition switch ON.
4. Use SSM3 to read DTC.
  Criteria: U0401 is output
  
  NO: Go to "How to simulate trouble phenomenon" (Refer to PROCEDURES FOR MALFUNCTION PHENOMENON SIMULATION )
  
  YES: Go to next step
DTC check
1. Use SSM3 to read DTCs of all the systems.
  Criteria: U0401 is not detected from more than one module
  
  NO: Replace the engine control computer.
  
  YES: Go to next step
Replacement of the module
1. Replace the engine control computer.
2. Use SSM3 to read DTC.
  Criteria: U0401 is output
  
  NO: System is normal.
  
  YES: Go to next step
Replacement of the module
1. Reinstall the ECM.
2. Replace the module that DTC has been detected.
3. Use SSM3 to read DTC.
  Criteria: U0401 is output
  
  NO: System is normal.
  
  YES: Replace the ECM.