B1790

DTC B1790

CIRCUIT DESCRIPTION
The passenger presence system (PPS) communication circuit consists of the sensing and diagnostic module (SDM) and the PPS module. The SDM monitors the PPS communication circuit. If the SDM detects a malfunction within the PPS communication circuit, a DTC will be set.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B1790 Loss of SIR Communications

CONDITIONS FOR RUNNING THE DTC
Ignition 1 voltage is within the normal operating voltage range.

CONDITIONS FOR SETTING THE DTC
The SDM detects a PPS communication circuit malfunction.

ACTION TAKEN WHEN THE DTC SETS
The SDM commands the AIR BAG indicator ON.

CONDITIONS FOR CLEARING THE DTC
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

DIAGNOSTIC AIDS
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:
- An open or high resistance in the PPS communication circuit
- A short to ground or voltage in the PPS communication circuit
- A short between the PPS communication circuits
- An internal PPS module malfunction
- An internal SDM malfunction

If an intermittent malfunction exists, refer to Diagnostic Aids for Circuit Testing and Wiring Repair procedures.

TEST DESCRIPTION

Steps 1 - 9:

The numbers below refer to the step numbers on the diagnostic table.
5. This step tests the PPS communication circuits for an open or high resistance, short to ground or short to voltage.
7. This step tests to see if the malfunction is caused by the PPS module.