No, the block heater shouldn't have anything to do with it. I'm assuming the car starts and runs, we just have a check engine light, right? Do this. With the key on, not running, push and hold the info button up, and the on/off together until we get into what is called segment check. All display segments will light, release buttons. It should show 'all?', Pushing info down will start scrolling through modules(aprox 22) in alphabetical order. Scroll until you reach 'PCM', push the info up, and you will either see 'PCM codes', or 'PCM clear codes'. Info down will toggle between one, or the other, we want PCM codes. When 'PCM codes' is on the info center, push info up to select. Have a pen and paper to write down which codes you have. You might have one, or multiple. It should say which is current, and which is history. Regardless, if there is multiple codes, let's clear them. Push on/off button and it should back up to the PCM codes/PCM clear codes option. Select clear codes with info down, and execute with info up, it should say codes cleared or no pcm codes. Cycle the key, and drive, or do whatever until the check engine light comes back on. Repeat above procedure, and this will relate to your fault. You can end diagnostics by turning the key off, or pressing any button on the left side(eng/met, info reset, etc. Hopefully this helps, there may be discrepancies in my instructions, since in the 11 years I have been with Cadillac, there have been some variances in the On-Board diagnostic architecture. Let me know your success
Friday, February 20th, 2009 AT 11:00 PM