Cadillac Sedan DeVille DTC E012
Repair Advice for a 1992 Caddy Sedan That Won't Start and Has a DTC
Readers' auto repair questions answered about a 1992 Cadillac Sedan DeVille with an ignition code.
This weekly Q&A session answers your questions about cars and trucks. This week explores a 1992 Cadillac Sedan DeVille that won't start.
Question:
I have a 1992 Cadillac Sedan DeVille with a 4.9 liter V-8 engine and have the error code E-12 - No distributor signal. How can this be repaired or eliminated?
Thanks,
Lloyd Sanchez
Answer:
DTC E012 indicates "No distributor signal". This code can be stored as a "current" or "history" code. If the PCM does not see distributor reference pulses for 4.0 seconds with cam reference pulses being received, current code E012 will be set.
Possible causes of "no distributor reference" are:
- The grounding screw is located on the metal tab that is attached to the plastic fitting on the five-wire harness.
- HEI module unable to process pick up coil signals to produce distributor reference pulses.
- Open or shorts on CKT 430 from distributor module to PCM.
- Defective pick up coil.
There is a diagnostic tree that goes with this code to troubleshoot it. In a nutshell the possible causes are a bad distributor pickup, a bad High Energy Ignition (HEI) module, a wiring problem or a bad Powertrain Control Module (PCM).
The first thing to check for is that all the connectors are clean and tight and that the wiring is undamaged.
The diagnostic tree is posted here for you to use. Be careful to follow the tree exactly as it is laid out. If you skip a step then the results are invalid. This one is not difficult to follow so just take your time and go step by step. Here are some important notes for the diagnostic tree.
- Checking for proper voltage output of the HEI system. If the voltmeter shows .5 to 2.8 volts, then HEI is producing reference pulses.
- Checking for proper ground connection between the PCM and the HEI module.
- Checking for proper voltage through CKT 43O from HEI to the PCM. If PCM terminal D8 sees .5 to 2.8 volts, then the PCM is receiving reference pulses.
- Checking for HEI module operation. If the HEI system will produce a spark then fault is not at the pick up coil or module.
For more information on how to troubleshoot an electrical problem read Troubleshooting the Electrical System.
That's all for this week. Feel free to browse the archives for past topicsand other resources. And, as always, if you are stuck and need an immediate answer you can always call Vince on the phone.
