How to Troubleshoot a Chevy Lumina PCM
- 1). Page through your OBD-II scanner's manual and bookmark the pages listing generic OBD-II codes universal to all vehicles made after 1996.
- 2). Print out Chevrolet's OBD-II codes off of the internet. These will be General Motor's supplemental trouble codes. The Lumina's manual will not have these codes. However, a Haynes or Chilton repair manual will, and you will find it the chapter dealing with emissions.
- 3). Read through the materials and highlight all the trouble codes dealing with the PCM. Code P1621, for example, deals with the PCM's memory and its perfomance. Place all the highlighted material into your Lumina's navigator seat.
- 4). Walk around the car and climb into the driver's seat. Connect your OBD-II scanner to the Lumina's diagnostic computer port. This data link connector can be found under the dash, above the gas pedal.
- 5). Turn the Lumina's electrical array on, and depending on your brand of scanner, possibly the engine too. Look at the scanner's display, and key in a retrieval code, if your brand of scanner was not prefigured to automatically do so. Since all scanners are manufactured slightly differently, consult the scanner's manual for precise instructions.
- 6). Scroll through the codes reported on your scanner's display. Look only for the PCM related codes you highlighted earlier. If there are no PCM related codes on the scanner's display, then the component is fine. Seriously consider, however, troubleshooting any unrelated, non-PCM codes reported by your scanner.
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