Circuit/System Description

WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. When the SDM has completed the power-up mode, the SDM will establish communication with the passenger presence system (PPS). The PPS will respond by requesting both of the PASSENGER AIR BAG ON/OFF indicators to illuminate for 5 seconds. The SDM will then transmit a request message to the PPS to receive the PPS verification ID. The PPS will transmit the verification ID to the SDM, and the SDM will compare the ID received to data stored in memory. If the data stored in memory does not match the information transmitted by the PPS or the SDM has detects that the PPS has set a current DTC the SDM will then disable the instrument panel (I/P) module deployment loop, set DTC B0081 and illuminate the AIR BAG warning indicator.

The SDM sends a message to the PPS, when commanded by the scan tool to initiate the DTC retrieval process. This process will take some time, about 13 seconds. When the PPS receives a request for DTCs, it will illuminate both PASSENGER AIR BAG ON and OFF indicators. After the PASSENGER AIR BAG ON and OFF indicators have illuminated for 3 seconds, cycle the ignition OFF and then turn the ignition back ON. After the PPS receives this request for data, it will transmit the DTC data to the scan tool through the SDM. This data is accessible for one ignition cycle only. Do not turn the ignition OFF while displaying PPS DTCs.