Clearing Diagnostic Trouble Codes (Resetting the Control Module)

In the event of a PGM-FI system electrical malfunction, a dash mounted indicator lamp will light and stay lit. If the dash warning lamp is on, or if a system malfunction is suspected even though the lamp is off, it is necessary to check the electronic control unit LED display. The LED display is on the ECU, and the indicator lamps operate whenever the ignition is on and a trouble code is stored in the ECU memory.
The ECU contains four LED's, numbered 1, 2, 4 and 8 when counted from right to left. When the warning lamp on the dash is lit and a failure code is stored in the ECU memory, the LED indicators will be illuminated to indicate the failure code.
System diagnosis requires the use of a suitable digital multimeter and system checker harness 07999-PD6000A. The harness checker allows test connections to be made at the ECU, while leaving the main harness connectors connected.
To diagnose system malfunctions start with TROUBLE CODE DIAGNOSIS / DIAGNOSTIC CHARTS-START DIAGNOSIS HERE. If a problem cannot be resolved using the preliminary self-diagnosis chart, proceed to PGM-FI SELF-DIAGNOSIS CHARTS. Read through charts noting bold faced type and locate chart that corresponds with the code, most closely describes the symptom, and/or operation of warning lamp and LEDs. Follow tests exactly and repair any malfunctions found before proceeding to next step. After completing diagnosis and repairs, clear self-diagnosis codes by disconnecting the battery ground cable for at least 10 seconds. After connecting the cable, check to see that the LED display is turned off. After completing diagnosis and repairs, clear self-diagnosis codes from memory by disconnecting the battery ground cable for at least 10 seconds. After connecting the cable, check to see that the LED display is turned off.