TROUBLE SHOOTING
Note. Observe PGM-FI or Check Engine warning light. If light is on and no codes are flashed by LED on ECU, this indicates that backup system is in operation. See LED DOES NOT FLASH under CODE 0, NO CODES in TESTING section of this article.
EMISSION TEST FAILURE
Check MAP sensor, oxygen sensor, all emission control systems, crank angle sensor and coolant temperature sensor.
TESTING
Note. Before starting testing, ensure engine is in good mechanical condition and adjusted to specifications.
On all models, an LED is located on ECU for self-diagnostic codes. LED is used to read codes set due to component failure. When the Check Engine warning light has been reported on, pull down the passenger's side carpet from under the dashboard, turn the ignition on, and observe the LED on the top of the ECU. The LED indicates a system failure code by blinking frequency. The ECU LED can indicate any number of separate or simultaneous component problems by blinking codes, one after another. (Scheme 46) See appropriate LED CODES table in this article.
Note. If unlisted codes are flashed by ECU LED, clear codes and recheck. If code still appears, substitute a known good ECU. If condition is rectified, replace original ECU.
On all models, System Checker Harness (07999-PD60000A ) is needed to test components. (Scheme 47) This device function as breakout boxes to access pin voltage signals while component is either in or out of circuit.
To reset ECU, remove hazard fuse in main fuse box for 10 seconds.
| LED Blinks | System Code |
|---|---|
| 0 | ECU |
| 1 | Oxygen Sensor |
| 3 | MAP Sensor |
| 4 | Crank Angle Sensor |
| 5 | MAP Sensor |
| 6 | Coolant Temperature |
| 7 | Throttle Angle Sensor |
| 8 | TDC Sensor |
| 9 | No. 1 CYL Sensor (HF & Si) |
| 10 | Intake Air Temperature |
| 11 | IMA Sensor (Without O2 & Catalyst) |
| 12 | EGR System (HF) |
| 13 | Atmospheric Pressure Sensor |
| 14 | Electronic Air Control Valve |
| 15 | Ignition Output Signal |
| 16 | Fuel Injector |
| 17 | Vehicle Speed Sensor |
| 19 | Lock-Up Solenoid Valve (Auto. Trans.) |
| 20 | Electric Load Detector |
CIVIC LED CODES
