Cadillac Repair: 1998 DeVille Diagnostic Codes, spark plug wires, spark plug wire

Question
The car is giving 4 diagnostic codes, I will list them in order they appeared.  Note that the battery was disconnected about a month ago, so these are recent codes. I do not have any way of knowning what they mean.

PCM P0300 current.
PCM P0603 history.
SDM B1328 history.
IRC B1982 history.

Thank you

Answer
You either have a faulty spark plug wire or spark plug in one of the cylinders.

If you have a diagnostic scanner, E-mail: [email protected] for a complete diagnostic chart to follow using the scanner to detect which cylinder is mis-firing.


Another simple way is to wet down all the spark plug wires at night using a windex bottle filled with water and after you wet down all the spark plug wires, start the engine and see if you can see any arching spark plug wires.