ecm trouble codes

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LOOTZ
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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.
Jan 10, 2006 at 12:26 PM
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2CARPRO JACK
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LOOTZ
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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.
Jan 11, 2006 at 8:04 AM
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GUITARMAN5
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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
Mar 13, 2006 at 2:48 AM
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MVANNESSJR
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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
Mar 13, 2006 at 9:56 AM

Suggested Repair

Code 52 means the ECM did not sense the CALPACK at power-up. Check that the correct CALPACK is properly installed, verify the PROM is the correct unit and fully seated, and suspect a defective ECM if those checks are good. Code 12 only indicates diagnostic mode.

Conversation Summary

The owner of a 1985 Chevy Celebrity 2.8L MPFI asked for ECM trouble-code definitions after a cold start that ran rough for a few minutes, then flashed codes 12 and 52 while idle rose until the engine had to be shut off. Earlier codes 12, 24, 44, 52, and 54 reduced to 12 and 52 after the battery was disconnected. Replies identified code 12 as diagnostic mode and code 52 as a CALPACK or ECM fault, with possible causes including a missing, incorrect, or poorly installed CALPACK, a defective or incorrectly inserted PROM, or a defective ECM.

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