"CHECK ENGINE" LIGHT
All models are equipped with a "CHECK ENGINE" light. As a bulb check, light will illuminate when the ignition is on and engine is not running. "CHECK ENGINE" light will also illuminate when a system failure has been detected, and a corresponding trouble code has been set in ECU memory. Not all trouble codes will activate "CHECK ENGINE" light.
Hard failures cause "malfunction" light to illuminate and remain on until the malfunction is repaired. If light comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined using diagnostic (code) charts. If a sensor fails, control unit will use a substitute value in its calculations to continue engine operation. In this condition, vehicle is functional, but loss of good driveability will most likely be encountered.
Intermittent failures may cause "malfunction" light to flicker or illuminate and go out after the intermittent fault goes away. The corresponding trouble code, however, will be retained in control unit memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from control unit memory. Intermittent failures may be caused by sensor, connector or wiring related problems. See INTERMITTENTS in TESTS W/O CODES article.
NOTE:Before starting tests, ensure engine is in good mechanical condition and adjusted to specifications.
When the "CHECK ENGINE " light has been reported as being on, turn ignition switch to the "ON" position. Pull down the inspection window from under the passenger seat. Observe the LED on the top of the ECU. The Red LED indicates a system failure code by blinking at a certain frequency.
All codes indicated by the blinks will be followed by a 2-second pause. One blink with a 2-second pause indicates a Code 1. Two blinks followed by a 2-second pause indicates a Code 2 etc.
To test the circuits for each code, remove the front passenger seat to gain access to the ECU. Connect PGM-FI Test Harness (07999-PD6000A ) to the ECU as described for the test for each particular code. Proceed with the test following the steps outlined for that test.
Tuesday, December 30th, 2008 AT 8:27 PM