pontiac firebird ecm failure.why?

5

Asked by Jun 04, 2011 at 09:30 PM about the 1983 Pontiac Firebird

Question type: Maintenance & Repair

hi guys. my 1983 5.o crossfire blew an ecm.until this point car was running fine.checked for obvious bare wires etc,found nothing.jumped terminals A+B can't extract a code [seems like it's that part of the computer thats  blown. fitted a new box today,car started fine and ran well for a  few minutes put car int drive and the box went again.[i think all was ok until this point]. any suggestions .MARK.

4 Answers

265

Corrosion or damage due to moisture is one of the main reasons for ECM failure. Corrosion can enter the ECM through the wiring harness and moisture can enter by a failure in the seals in the ECM itself. This happens over a period of time (5 to 10 years) due to the ECMs exposure to the elements. The electronic fuel solenoid is also a main reason for failure in the ECM. The solenoid can cause a short in the ECM due to corrosion in the solenoid or the wire running from the solenoid to the ECM harness. The electronic fuel solenoid is located at the top of the fuel pump. The solenoid seems to fail due to corrosion as fast or faster then the ECM. If the car is running fine then you shut your engine off and it will not restart then this is a good indication that the starter has shorted out the ECM. The third thing that can cause failure in the ECM is the Injector wiring harness or the sensor wiring harness. Once again corrosion or breaks in the internal wiring in the harness can cause a short in the ECM or corrosion can enter the ECM through the wiring harness. Again this is caused by exposure to the elements. If your check engine light is on then you should be able to read a fault code from your ECM. The fault codes should help identify where the problem is originating from. But ECM failures occur from overvoltage, shorted outputs, and transients usually.

265

Personally the best way is to take it to shop and have a tech look at it for sure. P.S. if you ever decide to sell the Trans Am, I'll buy it from you To Keep In #1 Original Condition :-)

5

hi, thanks for the response.I have checked the wiring harness,inside the car and out and cannot see anything obvious.however,the alternator has died.[this has been checked by 2 different places] neither can get any reading out of it so it musyt be pretty severe. also the charcoal canitster purge solanoid is not working [seized] this ,i believe is on the same quad driver that has blown.not quie sure what to do next i am now waiting for the alternator to come back from being re built.but i am having no end of trouble getting someone to plug the car in [i am uk based]although the "check engine" light is on when the ecm failes it will no longer flash the trouble codes presumably this is on the circuit that has gone..once again,thanks for the reply.will keep you posted. MARK.+[ a very poorly] K.I.T.T.

265

It's good mark, probably being UK based you might not have all The places we have here for parts of the F-body or mechanics that are used to having so many come In. But yes keep me posted, if you ever want to part with it, I'll be glad to turn it into a Showroom K.I.T.T. that will make jaws drop :-)

Your Answer

Add photo
Firebird

Looking for a Used Firebird in your area?

CarGurus has 742 nationwide Firebird listings starting at $2,500.

ZIP:

Search Pontiac Firebird Questions

Pontiac Firebird Experts

#1 Samuel Moore
Samuel Moore
Reputation 930
#2 dandyoun
dandyoun
Reputation 780
#3 John Saffrahn
John Saffrahn
Reputation 700
View All

Related Models For Sale

Used Chevrolet Camaro
151 Great Deals out of 32,811 listings starting at $1,995
Used Ford Mustang
370 Great Deals out of 47,056 listings starting at $1,999
Used Chevrolet Corvette
102 Great Deals out of 20,418 listings starting at $3,495
Used Dodge Challenger
111 Great Deals out of 24,127 listings starting at $9,350
Used Dodge Charger
282 Great Deals out of 27,138 listings starting at $2,250
Used Chevrolet Monte Carlo
15 Great Deals out of 1,411 listings starting at $1,995
Used Pontiac Grand Prix
24 Great Deals out of 2,909 listings starting at $1,995
Used Ford F-150
2,228 Great Deals out of 208,930 listings starting at $1,499
Used Chevrolet Impala
503 Great Deals out of 29,657 listings starting at $799

Used Cars For Sale

2002 Pontiac Firebird For Sale
115 listings starting at $4,295
2001 Pontiac Firebird For Sale
67 listings starting at $3,488
2000 Pontiac Firebird For Sale
66 listings starting at $2,500
1999 Pontiac Firebird For Sale
51 listings starting at $5,999
1998 Pontiac Firebird For Sale
34 listings starting at $6,900