Circuit Description
WARNING: This page is about a different car, the 2002 Pontiac Grand Prix, 2002 Chevrolet Malibu, and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
The Powertrain Control Module (PCM) receives rough road information from the Electronic Brake Control Mode/Electronic Brake And Traction Control Module (EBCM/EBTCM) on the 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/EBTCM transmits rough road information based on inputs from the wheel speed sensors. If EBCM/EBTCM detects a condition which will not allow the EBCM/EBTCM to properly identify rough road situations while a misfire condition is being detected by the PCM, DTC P1380 will be set.