Powertrain Controls - ECM/PCM

DESCRIPTION


The PCM receives analog voltage signals from various sensors and converts them to digital square waves. If there is a problem with the conversion process, Code 55 will set.

CODE PARAMETERS

^ Code 55 will set if:


^ The analog to digital conversion takes too long.


^ The low voltage of a square wave is greater than 0.1 volt.


^ The high voltage of a square wave is less than 4.88 volts.

DIAGNOSTIC AIDS

^ Code 55 indicates an internal PCM malfunction. The PCM should be replaced.