Powertrain control module: Difference between revisions

Revision as of 16:38, 25 June 2014

Revision as of 12:41, 23 July 2014

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*P0608....Control Module VSS Output

If you see any of these codes when diagnosing the vehicle with a code reader or scan tool, it may mean the PCM has failed and must be replaced. There can be other reasons for these codes as well, so the presence of any of these codes does not definitively mean the PCM needs to be replaced. Additional diagnostic tests will usually be necessary to confirm the problem is really the power-train control module and NOTnot something else. Refer to the OEM diagnostic charts for what these tests are. Usually it involves checking certain inputs to the PCM to see if it outputs the correct response. No response or an incorrect response usually means the PCM is defective and needs to be replaced. Professional Automotive Technicians use extremely expensive equipment ($4,000 to $8,000) to do the extensive and complicated diagnostics that are required before eliminating all other possibilities, to be able to arrive at a firm conclusion that the PCM has failed.

The primary inputs to the PCM come from many sensors, of different types, that are spread around the car. Most of them are oriented toward engine management and performance. These sensors fail at a much higher rate than any of the computers do.