Circuit Description

The Powertrain Control Module (PCM) receives rough road information from the Electronic Brake Control Module (EBCM) or the Electronic Brake And Traction Control Module (EBTCM) on the Class 2 serial data circuit. The PCM uses the rough road information to enhance the misfire diagnostic by distinguishing crankshaft speed variations caused by driving on rough road surfaces from variations caused by true misfires. The EBCM or EBTCM transmits rough road information based on inputs from the wheel speed sensors. If the EBCM or EBTCM detects a condition which will not allow it to properly identify rough road situations while a misfire condition is being detected by the PCM, DTC P1380 will be set.