Circuit Description

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The ESC module receives a chassis pitch angle information from the PCM on the chassis pitch angle signal circuit. Under normal conditions, this signal is 5 volt (+/- 0.5 volt) ref. The PCM then grounds the chassis pitch signal circuit when the vehicle is accelerating rapidly or braking hard. When the PCM grounds the chassis pitch angle signal circuit, the circuit goes low to about 0 volts, the ESC module commands all 4 shock absorber solenoids to a firm position. The PCM calculates the chassis pitch information based on the engine torque and the vehicle braking force. The ESC module also performs a test on the chassis pitch angle circuit when the ignition switch is turned to RUN. The ESC module sends a chassis pitch request to the PCM on the serial data line. The PCM then grounds the chassis pitch input circuit, pulling the circuit low for 5 seconds and returns to normal operation.