The passenger presence system (PPS) monitors itself for faults and will set flash DTCs if a fault is detected. The PPS communicates with the inflatable restraint sensing and diagnostic module (SDM) via non-class 2 communications. When the SDM receives input from the PPS that a PPS fault has occurred, the SDM will request the instrument panel cluster (IPC) to turn the AIR BAG indicator located on the IPC ON. To determine what DTCs have been set by the PPS, the scan tool is used to command the SDM to request the PPS to flash the DTCs using the PASSENGER AIR BAG ON/OFF indicators located on the rearview mirror. The scan tool sends a string of commands to the SDM that allows the SDM to communicate with the PPS module and initiate the flashing of the DTCs. When the scan tool has completed sending the commands, the PPS will begin flashing any current or history DTCs that the system has stored. When the SDM no longer receives commands from the scan tool, the SDM mistakes this as a communication fault and sets DTC U1241. DTC U1241 will set when the scan tool is used to flash DTCs from the PPS or after the PPS has been rezeroed. DTC U1241 does not indicate a system malfunction and will not cause any warning indicators to illuminate. When DTC U1241 sets, cycle the ignition and use the scan tool to clear the code, no further diagnosis is necessary. For more detailed description and operation concerning the PPS, refer to SIR System Description and Operation . For more detailed information concerning PPS flash code and rezeroing procedures, refer to Passenger Presence System Flash Code Procedures and Passenger Presence System Rezeroing .

This diagnostic procedure supports the following DTC:

DTC U1241 Lost Communication With Scan Tool

Ignition 1 voltage is within the normal operating voltage range.

DTC U1241 will set when the scan tool is used to flash DTCs from the PPS or after the PPS has been rezeroed.

You issue a scan tool CLEAR DTCs command.

DTC U1241 does not indicate a system malfunction and will not cause any warning indicators to illuminate. When DTC U1241 sets, cycle the ignition and use the scan tool to clear the code. No further diagnosis is necessary.