B0127

CIRCUIT DESCRIPTION
The seat belt buckle switch circuit consists of a seat belt buckle switch and the SDM. The SDM monitors the seat belt buckle switch for a buckled/unbuckled state. If the SDM detects a malfunction within the seat belt buckle switch circuit, a DTC will be set.

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

CONDITIONS FOR SETTING THE DTC
The SDM detects a malfunction in the seat belt buckle switch circuit.

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 seat belt buckle switch - left circuit
- A short to ground or voltage in the seat belt buckle switch - left circuit
- A malfunctioning seat belt buckle switch
- An internal SDM malfunction

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

TEST DESCRIPTION

Steps 1-2:

Steps 3-6:

Steps 7-9:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests the seat belt buckle switch (unbuckled) for the proper resistance value.
4. Tests the seat belt buckle switch (buckled) for the proper resistance value.
6. Tests for an open, short to ground, or short to voltage in the seat belt buckle switch - left circuit.