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Self-Diagnostic Codes

The System Checker Harness (07999-PD6000A ) is needed to test components.

To reset ECU, remove alternator sense fuse in the under hood relay box for 10 seconds.

A Red LED light is located on ECU for self-diagnosis codes. There is also a Yellow LED light which is for idle speed adjustment and is not related to trouble shooting codes. The Red LED light is for codes set at component failure. See appropriate LED CODES table in this article. To obtain ECU codes, turn ignition switch to the "ON" position and watch ECU Red LED light. See Fig 1 . See COUPE LED CODES  or SEDAN LED CODES  table.

Fig 1: Retrieving Codes
G00275682Courtesy of AMERICAN HONDA MOTOR CO., INC.
COUPE LED CODES

LED Blinks (1) System Code
0 ECU
1 Front Oxygen Sensor
2 Rear Oxygen Sensor
3 & 5 MAP Sensor
4 Crank Circuit of Crank/CYL Sensor
6 Coolant Temperature Sensor
7 Throttle Angle Sensor
8 TDC Sensor
9 CYL Circuit of Crank/CYL Sensor
10 Intake Air Temperature Sensor
12 EGR System
13 Atmospheric Pressure Sensor
14 Electronic Idle Control Valve
15 Ignition Output Signal
17 Vehicle Speed Pulser
18 Ignition Timing Adjustment
(1) If unlisted codes appear, recheck codes. If unlisted codes are still present, replace the ECU with one known good and recheck.
SEDAN LED CODES

LED Blinks (1) System Code
0 ECU
1 Front Oxygen Sensor
2 Rear Oxygen Sensor
3 & 5 MAP Sensor
6 Coolant Temperature Sensor
7 Throttle Angle Sensor
8 TDC Sensor
9 CYL Crank Angle Sensor
10 Intake Air Temperature Sensor
11 Idle Mixture Adjuster (IMA) Sensor
12 EGR System
13 Atmospheric Pressure Sensor
14 Electronic Idle Control Valve
(1) If unlisted codes appear, recheck codes. If unlisted codes are still present, replace the ECU with one known good and recheck.