c4newbie

I'm New Here
Sep 17, 2016
6
0
Lindsay Ontario
VetteCoins
501
Car
Corvette 1985
i have a 1985 with 57000 original kilometers and its a manual transmission. after driving for 20 to 30 minutes engine light comes on . no changes in performance all gauges reading normal. when i stop and turn it off , come back to it light is off for another 20 to 30 minutes of driving. i have replaced egr valve new gas cap still no change. really looking for some advice ..thanks
 
Other than suggesting buying (or finding someone with) a code reader, I can't help ya newbie. Code readers are cheap as borsch on Amazon.... Good Luck.
 
i have a 1985 with 57000 original kilometers and its a manual transmission. after driving for 20 to 30 minutes engine light comes on . no changes in performance all gauges reading normal. when i stop and turn it off , come back to it light is off for another 20 to 30 minutes of driving. i have replaced egr valve new gas cap still no change. really looking for some advice ..thanks
thanks buddy
 
You can pull codes by shorting pins A &B on the ALDL count the flashes

aldl.gif

Pin "B" is the diagnostic enable pin and pin "A" is ground. Grounding pin "B" to enable the diagnostic readout of the ECM/PCM.

To recover the codes, short pins "A" and "B" together using a small section of electrical wire or paper clip.

With the ignition turned OFF, short pins "A" and "B" on the ALDL.

Turn IGN ON (but not to RUN).

The "Check Engine" light (early C4s) or "SYS" light (later C4s) will flash a Code 12 (a single flash followed by two flashes) and will repeat three times (Flash (pause) Flash Flash (long pause), Flash (pause) Flash Flash (long pause), Flash (pause) Flash Flash (long pause).

Code 12 is a delimiter or marker code to show where the error code string begins and ends.

After the three Code 12 flashes, you will either get an error code (or codes) or you will get another string of Code 12 flashes if there are no trouble codes stored.

All codes are repeated three times with a long pause between each code group (36 or Flash Flash Flash pause followed by six flashes, repeated three times, folowed by a long pause with any additional codes stored then flashed).

The "Check Engine/System" light on with engine running means the condition(s) are currently present. If the light is not on during RUN operation, the limits were exceeded at some point in time and the event was recorded in memory, but the reading has since returned to the normal operating range.

Remember to remove the shorting device from the connector after you have read the codes.

Clearing the Codes

To clear the codes from memory, remove the negative battery cable for a minimum of 10 seconds.

Disconnecting the battery will clear all stored codes and and any stored memory (radio button presets, clock, trip odometer, average gas mileage memory, power seats). Your ECM/PCM computer will also have to relearn timing/mixture/exhaust emissions.

Make absolutely certain the ignition key is turned OFF. If you connect the battery with the ignition switch ON, you can destroy the ECM/PCM module.

Post your code and we can go from their
 
  • Like
  • Informative
Reactions: ddgermann and Nik
You can pull codes by shorting pins A &B on the ALDL count the flashes

aldl.gif

Pin "B" is the diagnostic enable pin and pin "A" is ground. Grounding pin "B" to enable the diagnostic readout of the ECM/PCM.

To recover the codes, short pins "A" and "B" together using a small section of electrical wire or paper clip.

With the ignition turned OFF, short pins "A" and "B" on the ALDL.

Turn IGN ON (but not to RUN).

The "Check Engine" light (early C4s) or "SYS" light (later C4s) will flash a Code 12 (a single flash followed by two flashes) and will repeat three times (Flash (pause) Flash Flash (long pause), Flash (pause) Flash Flash (long pause), Flash (pause) Flash Flash (long pause).

Code 12 is a delimiter or marker code to show where the error code string begins and ends.

After the three Code 12 flashes, you will either get an error code (or codes) or you will get another string of Code 12 flashes if there are no trouble codes stored.

All codes are repeated three times with a long pause between each code group (36 or Flash Flash Flash pause followed by six flashes, repeated three times, folowed by a long pause with any additional codes stored then flashed).

The "Check Engine/System" light on with engine running means the condition(s) are currently present. If the light is not on during RUN operation, the limits were exceeded at some point in time and the event was recorded in memory, but the reading has since returned to the normal operating range.

Remember to remove the shorting device from the connector after you have read the codes.

Clearing the Codes

To clear the codes from memory, remove the negative battery cable for a minimum of 10 seconds.

Disconnecting the battery will clear all stored codes and and any stored memory (radio button presets, clock, trip odometer, average gas mileage memory, power seats). Your ECM/PCM computer will also have to relearn timing/mixture/exhaust emissions.

Make absolutely certain the ignition key is turned OFF. If you connect the battery with the ignition switch ON, you can destroy the ECM/PCM module.

Post your code and we can go from their
thank you very much
 
Old Thread: Hello . There have been no replies in this thread for 100 days.
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

Similar threads

Users who are viewing this thread