SELF-DIAGNOSTIC SYSTEM
Hard Failures
Hard failures cause malfunction indicator light (CHECK ENGINE) to illuminate and remain on until problem 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. See CODE CHARTS. If a sensor fails, control unit will use a substitute value in its calculations to continue engine operation. In this condition, commonly known as limp-in mode, the vehicle runs but driveability will not be optimum.
Intermittent Failures
Intermittent failures may cause CHECK ENGINE light to flicker or illuminate and go out after the intermittent fault goes away. However, the corresponding trouble code will be retained in ECU memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from ECU memory. Intermittent failures may be caused by a sensor, connector or wiring related problems.
RETRIEVING CODES
Accessing Trouble Codes
1 - Open the Diagnostic Module, and in the lid that flips open is a chart that tells you what each pin (the little connectors) is. You need to locate the pin labeled "TEN" and another labeled "GND." Using a paperclip or a piece of wire, connect, or "jumper" these two pins together. Some people have reported that their "GND" pin does not exist (has no connector, just an empty hole); this is ok, "GND" stands for "ground." If you DO NOT have a "GND" pin, then simply connect the "TEN" pin to the negative terminal of your battery (a.k.a. ground).
2 - Put your key in the ignition, but do not start your car. Turn the key into the "ON" position. Your Check Engine Light should turn on momentarily (a few seconds) and then turn off. Then, it will start flashing a certain number of times. A LONG flash indicates a "10" and a short flash indicates a "1." You add them together to determine the Trouble Code. So, for example, 2 long flashes followed by 3 short ones would equal "10 + 10 + 1 + 1 + 1" which is 23. There is a pause between error codes, and it repeats the codes over and over until you turn the key off.
INTERPRETING CODES
Identify the first (tens) and second(ones) digits of each code as follows: The first (tens) digit will display (flash) for about one second for each count, with a one-half second pause between counts. For example, if the first (tens) digit is three, there will be three separate one second long flashes, separated between by one-half second pauses.
There is then a 1.6 second pause between the last flash of the first digit and the beginning of the second (ones) digit.
The second (ones) digit counts flash for only one-half second each, with pauses of one-half second between them. For example, if the second (ones) digit is seven, then there will be seven flashes of one-half second, separated by pauses of one-half second.
In this example, the displayed code will thus be "37".
The system will then pause for four seconds before proceeding to the next code, if any.
AFTER-REPAIR PROCEDURE
After indicated service or replacement is performed, clear codes. Recheck PCME memory. No codes should be present. If codes are present, see appropriate trouble code chart under CODE CHARTS to repair vehicle.
CLEARING CODES
1) Disconnect negative battery cable. Depress brake pedal for at least 20 seconds. Reconnect battery cable.
2) Ground test connector with jumper wire. Turn ignition on, but DO NOT start engine for 6 seconds. Start and run engine at 2000 RPM for 2 minutes. Verify no codes are displayed.
NOTE: Trouble Codes No. 6, 12, 55, 60, 61, 62 and 63 are automatic transmission related problems. If codes are present, see appropriate TRANSMISSION SERVICE & REPAIR article.
92-93 CODES (1.6L SOHC ENGINE)
94-96 CODES (1.6L DOHC ENGINE)
