Entering Diagnostic Mode
- Turn ignition "ON". "CHECK ENGINE" lamp should glow. Locate diagnostic terminal wires near MCU. Connect diagnostic terminal leads together (Brown and Black/Yellow wires) found near MCU. MCU will start to display trouble codes, in the "CHECK ENGINE" lamp.
- If any trouble codes are stored in MCU memory, the "CHECK ENGINE" lamp will flash 2-digit codes. Trouble codes will be displayed from lowest to highest numbered code. Each code is repeated three times before the next code sequence is displayed. The trouble codes will be repeated as long as the diagnostic terminals are connected.
MCU TROUBLE CODE IDENTIFICATION
| Code | Problem |
|---|---|
| 12 | No Ignition - Normal condition |
| 13 | Open Oxygen Sensor Circuit |
| 14 | Shorted Coolant Sensor Circuit |
| 15 | Incorrect Coolant Sensor Circuit |
| 16 | Open Coolant Sensor Circuit |
| 21 | Throttle Position Switch Circuits Connected at Same Time |
| 22 | Starter Signal Circuit |
| 23 | Output Terminal to Ignition Coil Grounded |
| 25 | Output to Vacuum Switching Solenoid Ckt Open/Grounded |
| 33 | Open or Shorted Fuel Injector Circuit |
| 35 | Ignition Power Transistor Open |
| 41 | Bad Signal From Crank Angle Sensor |
| 43 | No Idle Position Signal |
| 44 | Lean Oxygen Sensor Indication |
| 45 | Rich System Indication |
| 51 | Faulty MCU |
| 52 | Faulty MCU |
| 53 | Vacuum Switching Valve |
| 54 | Bad Ignition Transistor or Ground |
| 55 | Faulty MCU |
| 61 | Circuit to Air Flow Sensor Bad |
| 62 | Circuit to Air Flow Sensor Bad |
| 63 | No Vehicle Speed Sensor Signal |
| 64 | Fuel Injector Transistor or Ground |
| 65 | Continuous Signal From Throttle Position Switch |
| 66 | Open or Shorted Knock Sensor Circuit |