Inspection steps

WARNING: This page is about a different car, the 2014 Subaru BRZ. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Perform this procedure after performing until STEP 9 in "How to troubleshoot". (Refer to HOW TO TROUBLESHOOT )

Check DTC
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
Check DTC
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
Check DTC
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
Check DTC
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
Check DTC
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
Replace 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
Replace 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.