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Author Topic: Check Engine Light on at Times  (Read 4379 times)

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  • Message Board Member not current NFTAC Club Member
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  • Posts: 2
Check Engine Light on at Times
« on: July 21, 2007, 02:53:32 PM »
Please help.  My '82 Pontiac Trans Am has only 48,000 miles on it and runs excellant.  However, at times, mostly when I've been on the freeway for five to ten minutes the "Check Engine" light will come on.  It will stay on for several minutes only to turn off again.  It will stay off for several minutes and then cycle on and off again. 

I took it in for a tune-up.  I had new plugs, wires, distributor cap and belts put in.  It still runs great - but I'm having the same problem with the Check Engine light. 

Any ideas for me?   



  • Firebird & Trans Am Club Tech Staff
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  • Posts: 110
Re: Check Engine Light on at Times
« Reply #1 on: July 24, 2007, 10:43:26 PM »
HI: Mark

“The Engine Check Light That Won’t Go Away”

When the engine Check Light is on; Try to put your car’s ECM into it’s diagnostic mode with a small hand held Code Detector like a CP 9001 Code Detector from (Actron) note any trouble codes that may be stored in your cars ECM // {Electronic Control Module} Code 12 etc.? if any; and or note if the engine check light flashes intermittently.

If the engine check light flashes intermittently a possible cause is that you have a short in the ECM electrical system [wiring] caused by loose connections and or frayed wires, and / or faulty grounding etc. in the circuit.

If a trouble code can be obtained when the “Check Engine” light is off or on with the engine running,( Using a Code Detector ) the trouble code must be evaluated to determine the fault. // note certain trouble such as code 13, 24, 44, 45 require engine operations under certain conditions such as part throttle, for a period of time before the “Check Engine”  light will come on. // also note that code 15 will set within 5 minutes of the engines operation

And finally a good rule thumb is that when you deal with a car with a on board computer you should always try too check your cars ECM and wiring to see if it’s good to go first, before you make any repairs otherwise you can be spending a lot money for replacement parts that where not originally needed!

    Hope This Helps  :)

                           Justin Kwarta
I am a NFTAC, Member and I was at one time an auto mechanic working for a local GM dealer here in my home town back in the mid-to late '80's now  I currently enjoy working on my own Pontiac's especially on my '85 T/A // making maintenance repairs, repairs, modifications and performance modifications I also enjoy meeting and /or talking to other Firebird & T/A owners an get into technical debates;hopefully just as long as the debate's doesn't go into a to heated argument.

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Re: Check Engine Light on at Times
« Reply #1 on: July 24, 2007, 10:43:26 PM »


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