Topic: ECM on a 81
in Forum: C3 Electrical
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OK the other day I was trying to smog my 81 in the great screwed up state of California and the guy tells me that I failed because there was no check engine light on the dash. So I tore into the instrument panel to check the bulb and there seems that I don't have a check engine light? Called a friend and he tells me my car was a Federal car and it does not have a ECM so there for no check engine light. I thought all 81's had ECM's? Is he right?
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Oak Creek, WI - USA
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Vette(s): 1981 Great White Shark. Red Interior, 350/190 hp. PS, PB (SS), A/C CC, T-Tops. Served three years in Active Duty Army, then Retired Air Force after 34 years! Badger State Vettes Car Club. 175,000 Original miles!! Now own a 1998 C-5!
1980 was the first year for the ECM. All 1981 had the Electronic Control Modual (ECM). As you look at the center instrument panel, the check engine light is on the left side, the plastic cover is divided into two lights, one is for "Fasten Seat Belts" and the other is the "check engine light". I have an 81 and I am looking at the shop manual as I type this!
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Oak Creek, WI - USA
Joined: 5/21/2008
Posts: 1965
Vette(s): 1981 Great White Shark. Red Interior, 350/190 hp. PS, PB (SS), A/C CC, T-Tops. Served three years in Active Duty Army, then Retired Air Force after 34 years! Badger State Vettes Car Club. 175,000 Original miles!! Now own a 1998 C-5!
Former Member
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Oak Creek, WI - USA
Joined: 5/21/2008
Posts: 1965
Vette(s): 1981 Great White Shark. Red Interior, 350/190 hp. PS, PB (SS), A/C CC, T-Tops. Served three years in Active Duty Army, then Retired Air Force after 34 years! Badger State Vettes Car Club. 175,000 Original miles!! Now own a 1998 C-5!
All of my research indicates that the 81 had the CCC (Computer Command and Control) or ECM. Lift up the ashtray in the consol and you will find the ALDL (Assembly Line Data Link). It was a standerd item on all 1981 Corvettes. and Jerry and David And Zora agree with me !!!
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The '81 should be exempt from smog inspections anyway, unless Colliefornia doesn't do that....
Just about every state exempts cars 25 years or older from smog inspections. And yes...all '81s had an ECM, as primitive as it may be.
In '80, only the Cali cars had the system, and even then it was on the 305 engines...no 350s in Cali for '80.
Just about every state exempts cars 25 years or older from smog inspections. And yes...all '81s had an ECM, as primitive as it may be.
In '80, only the Cali cars had the system, and even then it was on the 305 engines...no 350s in Cali for '80.
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Ok the car has a ECM so the next question is what would make the ck engine light to fail? I did ck the light bulb. The light runs off the crtys light fuse and it is good.
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Oak Creek, WI - USA
Joined: 5/21/2008
Posts: 1965
Vette(s): 1981 Great White Shark. Red Interior, 350/190 hp. PS, PB (SS), A/C CC, T-Tops. Served three years in Active Duty Army, then Retired Air Force after 34 years! Badger State Vettes Car Club. 175,000 Original miles!! Now own a 1998 C-5!
Do you know how to pull a trouble code from the ECM ? Look for the ALDL underneath the ashtray. Ground out the last two terminals together. You should see a series of blinking lights. 1 bling followed by two is a code 12, that just twells you that the ECM is ready to show you what is wrong. Watch for more flashing lights. The code 12 will flash up to five times then enter into diagnostic mode. different numbers will be displayed A Shop Manual for the 81 will describe them all. I can help as best I can !
Dan
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Oak Creek, WI - USA
Joined: 5/21/2008
Posts: 1965
Vette(s): 1981 Great White Shark. Red Interior, 350/190 hp. PS, PB (SS), A/C CC, T-Tops. Served three years in Active Duty Army, then Retired Air Force after 34 years! Badger State Vettes Car Club. 175,000 Original miles!! Now own a 1998 C-5!
Check the fuse for the ECM. It is also in the fuse block...10 amp fuse. Has the 81 been running for awhile? or has it been sitting idle, that important for me to know.
Former Member
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Oak Creek, WI - USA
Joined: 5/21/2008
Posts: 1965
Vette(s): 1981 Great White Shark. Red Interior, 350/190 hp. PS, PB (SS), A/C CC, T-Tops. Served three years in Active Duty Army, then Retired Air Force after 34 years! Badger State Vettes Car Club. 175,000 Original miles!! Now own a 1998 C-5!
Also, Adam is correct. Only Ca cars had the ECM in 1980. All 1981's had the computer system.
Dan I am assuming the car has been sitting for 12 years. The last time the car was registers was 1996. I do have a 81 shop manual and I will ck the fuse.
in Forum: C3 Electrical
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