Circuit Description

PCM uses rough road information to enhance misfire diagnostic by distinguishing crankshaft speed variations caused by driving on rough rod surfaces from variations caused by true misfires. The Electronic Brake Control Module (EBCM)/Electronic Brake Traction Control Module (EBTCM) transmits rough road information based on inputs from the wheel speed sensors. If a loss of communication occurs which causes the PCM not to receive rough road information while DTC P0300 is requesting MIL, DTC P1381 will set.