Self-Diagnostic Codes
On all models, a Red LED is located on ECU for self-diagnosis codes. Some Models also have a Yellow LED which is for idle speed adjustment and is not related to Red LED trouble shooting codes. The Red LED is for codes set due to component failure. See LED CODES table in this article. To obtain ECU codes, turn ignition switch to the "ON" position and count flashes of Red LED on top of ECU.
| LED Blinks | System Code |
|---|---|
| 0 | ECU |
| 1 | Front Oxygen Sensor |
| 2 | Rear Oxygen Sensor |
| 3 | MAP Sensor |
| 4 | Crank Angle Sensor |
| 5 | MAP Sensor |
| 6 | Coolant Temperature Sensor |
| 7 | Throttle Position Sensor |
| 8 | TDC Sensor |
| 9 | No 1 Cylinder Position |
| 10 | Intake Air Temperature Sensor |
| 12 | EGR System |
| 13 | Atmospheric Pressure Sensor |
| 14 | Electronic Air Control Valve |
| 15 | Ignition Output Signal |
| 17 | Vehicle Speed Sensor (Pulser) |
| 18 | Ignition Timing Adjustment |
On all Acura models a System Checker Harness (07999-PD60000A ) is needed to test components. An Inspection Adaptor (07GMJ-ML80100 ) is needed for testing specific sensors. This device function as breakout box to access pin voltage signals while component is either in or out of circuit.
To reset ECU, remove alternator sense fuse in the under-hood relay box for 10 seconds.