Description of On-Board Diagnostics

In the event of a PGM-FI system malfunction, a dash mounted indicator lamp will illuminate and stay On. When this condition occurs, it will be necessary to check the ECU LED display. On Integra models, the ECU contains a single red LED display, while Legend models contain a red and yellow LED. The red LED should be used for both models when diagnosing PGM-FI system malfunctions.
When the dash mounted indicator lamp is illuminated, move the front passenger seat to the rear position, turn on the ignition switch and observe the red LED on the front of the ECU. The LED will indicate a system failure code by blinking frequency and two second pauses. As an example, one blink, followed by a two second pause, followed by one blink and another two second pause indicates a failure code 1. Likewise, two blinks, followed by a two second pause, followed by two blinks and another two second pause indicates a failure code 2.
Some failure codes may require the use of system checker harness 07999-PD6000A and multimeter KS-AHM-32-003. When such usage is necessary, the front passenger seat must be removed and the harness and multimeter must be connected as shown, Fig. 1.
On Integra models, refer to wiring schematics, Figs. 2 and 3, failure code indicator charts, Figs. 4 and 5, and self-diagnosis charts, Figs. 6 through 29 to diagnose system failure codes. On Legend models, refer to wiring schematics, Figs. 30 and 31, failure code indicator charts, Figs. 32 and 33, and self-diagnosis charts, Figs. 34 through 62 to diagnose system failure codes. If failure codes other than those shown in the failure code indicator chart occur, recount the number of blinks of the LED. If these codes are indeed present, substitute a good ECU and recheck the indicated failure codes. If the failure code indications are eliminated, replace the ECU.