ECM trouble codes

LOOTZ

MEMBER
CHEVROLET IMPALA

Where can I get the trouble code (Check Engine light flashes) list for an '85 Chevy Celebrity V6 2.8L MPFI? Seems it should be available somewhere on the web, but I can't find one.

Present situation: Upon cold start in ambient 75 degree temp, engine rough for first two or three minutes; then as it beings smoothing out, the Check Engine light begins flashing codes 12 and 52, and the idle gradually increases until the engine is racing and needs to be turned off.

Temp-related, but it seems to occur too soon for the coolant temp to be involved. Exhaust temp or O2, I suspect, but I don't want to begin dismantling every sensor without a better clue, such as a code interpretation. After all, that's what they're there for.

Yesterday, I was getting a whole medley of codes (12 - 24 - 44 - 52 - 54) but they settled down to 12 and 52 after disconnecting battery to clear ECM memory.

Really would like a complete list of codes. Anything you can provide will be appreciated.

4 Replies

2CARPRO JACK

MECHANIC
11,533 POSTS

https://www.2carpros.com/kpages/reading_diagnostic_codes.htm

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Wednesday, January 11th, 2006 AT 3:30 PM

LOOTZ

MEMBER
5 POSTS

Nope, no relevant info on those pages (including 'trouble code tables). But I did finally find some good code lists for this type ECM elsewhere. Thanks for the effort.

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Wednesday, January 11th, 2006 AT 4:04 PM

GUITARMAN5

MEMBER
6 POSTS

Here you go, your welcome.

Code 12: diagnostic mode: 52: calpak or ecm problem:

if you send me an email, i'll give you the complete list.

Downtimeisit@hotmail. Com

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Monday, March 13th, 2006 AT 10:48 AM

MVANNESSJR

MECHANIC
223 POSTS

CODE 52

Trouble Code 52 indicates that the ECM sensed a fault in the CALPACK. The CALPACK is a module separate from the PROM that contains preset calibrations used by the system in the limp-home mode. The ECM checks for its presence at power up.

Code 52 gets set when:

- the ECM does not sense the CALPACK

Possible causes include:

1) Incorrectly installed CALPACK module

2) Incorrect CALPACK module for this vehicle

3) Defective or incorrectly inserted PROM

4) Defective ECM

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Monday, March 13th, 2006 AT 5:56 PM