HT4100 4.1, 4.5, 4.9 Discussion, '93 Eldorado 4.9L - P012 & P053 Codes in Cadillac Engine Technical Discussion; 1993 Eldorado 4.9L. Car has been running fine until today.....I was driving down a side street (~15mph)...then the engine stopped ...
1993 Eldorado 4.9L. Car has been running fine until today.....I was driving down a side street (~15mph)...then the engine stopped running. I have all electrical (i.e. lights turn on, radio turns on, starter engages and cranks), however, the engine will not fire.
I am getting codes P012 & P053 which appear to be related to a "distributor signal". Does anyone know what part would typically cause a no start condition and would trigger codes P012 & P053?
...she back up and going. Root cause was a faulty Ignition Control Module.
Here's a few notes that may help others that have a similar problems.....
1. Symptoms: The engine ran fine w/o any apparent problem, but while driving (or sitting in park) the engine would simply stop running. All other electricals were fine (i.e. lights/radio turned on, starter engaged and engine would turn/crank, but engine would not fire). The engine shutdown condition typically occurred after 5-10 minutes of engine run time. After 4-6 hours of sitting in ~30-40 F outside tempertures, the engine would start and run for another 5-10 minutes.
2. P012 Current and P053 History errors showed on the Instrument Panel Display.
3. The distributor cap was removed and the "bad" Ignition Control module was disconnected (i.e. removed the 3 connectors) and reconnected to determine if the electrical connections were faulty. The engine exhibited the same shutdown symptom. While the distributer is opened up, it is a good idea to test the resistance of the Pickup Coil (i.e. the Pickup Coil conector is the 2 pin connector located next to the 3 pin connector). I've seen 2 Resistance Specs....500-1500 ohm and 750-1000 ohm.....I suspect it just needs to be NOT shorted or NOT opened.
4. Here's a wierd one....the "bad" Ignition Control Module was taken to AutoZone for testing. The module continually passed the electrical test even after repeating the test about 15 times across 15 minutes. The module heated up...almost too hot to touch by one's hand. When installed in the distributer, the ICM may see higher temps which crosses a temperture threshold which causes its operation to fail.
5. Here's another wierd one....While the engine was in the fault (i.e. engine shutdown/no-run condition), I hooked up a timing light to 1 of the spark plug wires. My thoughts were that if the Ignition Module was bad, that the spark plugs would not be firing and the timing light would not strobe. I was amazed to see that the timing light DID strobe while the engine was in its shutdown condition. I suspect that a faulty Ignition module does not necessarily stop the plugs from firing (depending on which circuit inside the Ignition Module fails), but does stop the injectors from injecting (as indicated in the resources below).
Automobile(s): 1995 FWB 100,*** miles CURRENT. 1991 Seville 175,000 SOLD
Re: '93 Eldorado 4.9L - P012 & P053 Codes
Thank you for reporting the problem. I have seen many cases where components inside the distributor (among them ICM) were replaced...and replaced and replaced. Eventually the distributor itself was replaced and that solved the problem. Hopefully that's not your case. And thanks for the links!