How to Test the PCM on a Dodgeby Richard Ristow
A Dodge's powertrain control module (PCM) serves as the central computer for a vehicle's diagnostic system. The PCM analyzes sensor readings and engine functions. As soon as a component within the engine or fueling system malfunctions, the PCM issues a code and labels the problem either "trouble" or "pending." If the PCM were to cease working properly, your Dodge's diagnostic system would become untrustworthy. Testing this valuable device can be accomplished in a few minutes
Prepare some important materials before you check your Dodge's PCM. Consult your OBD-II (on-board diagnostic) scanner's handbook for a list of generic trouble codes. Also, find and print out Chrysler's supplemental OBD-II codes online and print them out. Take a highlighter to both and mark all the trouble codes that deal with the PCM itself. For example, P0601 denotes failure within the PCM itself. While testing the system, you should keep an eye out for it.
Place the coding resources in your Dodge's navigation seat. Then, get into the vehicle's driver's seat.
Locate your Dodge's computer outlet beneath the dashboard. The location of this data link connector depends on year and model of the Dodge. It may be beneath the steering wheel, next to the left kick panel or above the gas pedal.
Connect your OBD-II scanner to your Dodge's computer outlet. Switch the device on, and then turn the Dodge's electrical system on. You may own an OBD-II scanner that requires the engine to be running as well. Always keep in mind that no two scanner brands function exactly the same.
Look at your device's display screen. If there are no codes waiting for you, you own a scanner that is not preset for automatic code retrieval. Locate the procedure for entering a "Code scan" command. It usually entails pressing a button.
Scroll through the codes on the scanner's display screen. The PCM is part of the vehicle's powertrain. So you can safely exclude any OBD-II codes that start with "B," "C" or "U." Reference the source material you previously placed in the navigator's seat and look specifically for codes relating to the PCM's operations.
- PCM modules are used in vehicles after 1996. You cannot use an OBD-II scanner on Dodges with model years prior to 1996. Those vehicles are outfitted with an Electronic Control Module (ECM) and function differently.
Items you will need
- OBD-II scanner
- Car dashboard image by Andrejs Pidjass from Fotolia.com