Mass of codes

bowez

Registered User
Tach went crazy on the way to work and lost a lot of power, pulled these CM codes: 118 121 123 126 212 543
 
Tach went crazy on the way to work and lost a lot of power, pulled these CM codes: 118 121 123 126 212 543

hmmmmm..those make it sound like the tests were done on a cold engine not even running?

Can you confirm it was well warmed up and you went thru the testing procedure correctly?
 
118 - ECT voltage high or open
121 - TPS out of range
123 - TPS high or short to power
126 - Barometric sensor out of range
212 - Ignition tach signal erratic
543 - Fuel pump monitor circuit shows no power/fuel pump relay power feed open

When my '91 spouted codes very similar to those it turned out to be a bad PCM. I replaced so many $50+ sensors it was ridiculous. Replaced the PCM with a used one from Spinning Wheels SC, all codes cleared and are still clear to this day. Mine also showed a code 225 - knock sensor, and a 542 - fuel pump open. Best of luck.
 
I had just driven the car 15mins from work to home and temp was just fine and being CM codes there is no way of doing it wrong.
Only KOEO I get is the ever present 511 (Read Only Memory test failed) from it being chipped (had this one ever since got the car).

Is there an easy way to test the PCM short of swapping it out?

IF I'm looking right 543 and 212 could be O2s shorting out, but 118, 121 and 123 point to MAF?
 
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how does the harness look? solid/ clean ground connections at the battery, ground strap? battery/alternator issues? all those sensors can't go bad at once. I'd say harness short or open, bad ground or computer as mentioned above.
 
Symptoms, car will randomly die in idle, back fire and is starting to return to dieing with quick jabs to WOT, but if go slowing upto WOT seems to be fine. I've replace Cam, Crank Sensors and ICM.
 
Good morning

If the ignition switch is serviceable proceed with the inspection of the DIS harness as suggested in post #6 Mr. Figulaz. Remove the harness and look for:


Broken exposed wires, corrosion and or damaged pins at the CAM/CRANK sensor connectors. Don't forget about the shield ground wire.

The supercharger belt has not chaff against the CAM sensor connector of the harness.

Both DIS connectors for corrosion and or exposed wiring and or damaged pins.





Correct discrepancies or replace harness.
 
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