Seat Belt Indicator Circuit Malfunction - Passenger
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Seat Belt Indicator Circuit Malfunction - Passenger
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Diagnostic Fault Information
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Circuit
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Short to Ground
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High Resistance
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Open
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Short to Voltage
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Signal Performance
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Passenger Seat Belt Switch Signal
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1
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2
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2
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2
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-
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Passenger Seat Belt Switch Low Reference
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-
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2
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2
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2
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-
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1. Indicator will remain ON with seat belt buckled.
2. Indicator will illuminate only for the bulb check.
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Circuit/System Description
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When an individual is sitting in the passenger seat the passenger presence sensor detects the individual. A signal to the SDM indicates a person is in the passenger seat. The SDM enables the passenger seat belt indicator on when there is someone sitting in the passenger seat. The passenger seat belt switch is a 2-wire switch wired to the inflatable restraint sensing and diagnostic module (SDM) using a signal circuit and a low reference circuit. When the seat belt is unbuckled the switch is closed, and when the seat belt is buckled the switch is open. The SDM sends the status of the passenger seat belt via a hard wire to the passenger air bag disable indicator. The passenger air bag disable indicator will then control the illumination of the passenger seat belt indicator.
Schematic Reference
Seat Belt Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Seat Belt System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References
for scan tool information
Circuit/System Verification
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2.
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Have someone sit in the passenger seat.
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3.
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With a scan tool verify the Automatic Occupant Sensing Current Front Occupancy Status indicates Occupied.
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•
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Disconnect the harness connector at the K36 SDM.
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•
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Test for infinite resistance between the folowing circuits terminal and ground:
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-
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Sensor signal circuit terminal
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-
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Sensor low reference circuit terminal
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•
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Test for less than 2 Ω in each circuit end to end.
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5.
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With a scan tool perform the Passenger Seat Belt Reminder Indicator On/Off Control Function and verify the passenger seat belt indicator turns on and off.
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6.
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Replace the inflatable restraint instrument panel module indicator.
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7.
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Replace the inflatable restraint instrument panel module indicator.
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8.
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With the scan tool monitor the Passenger Seat Belt Status parameter while buckling and unbuckling the seat belt. The parameter should display Buckled and Unbuckled when buckling and unbuckling the seat belt.
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9.
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Refer to Circuit/System Testing below.
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10.
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Monitor the scan tool Passenger Seat Belt Switch parameter while connecting and disconnecting the seat belt switch connector. The parameter should display Buckled and Unbuckled when changing seat belt states. If the status does not change states refer to Circuit/System Testing below.
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11.
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Refer to Circuit/System Testing below.
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Seat Belt Switch Malfunction
2.
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Disconnect the harness connector at the appropriate B88 passenger seat belt switch.
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3.
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Test for less than 5 Ω between the ground circuit terminal B and ground.
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3.1.
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Disconnect the harness connector at the K36 SDM.
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3.2.
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Test for less than 2 Ω in each control circuit end to end.
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5.
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Verify the scan tool Passenger Seat Belt Status parameter listed below is Buckled.
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5.1.
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Disconnect the harness connector at the K36 SDM.
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5.2.
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Test for infinite resistance between the seat belt switch signal circuit terminal 2 and ground.
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6.
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Install a 3 A fused jumper wire between the signal circuit terminal A and the ground circuit terminal B.
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7.
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Verify the scan tool Passenger Seat Belt Status parameter is Unbuckled.
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7.1.
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Disconnect the harness connector at the K36 SDM.
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7.3.
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Test for less than 1 V between the signal circuit and ground.
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7.4.
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Test for less than 2 Ω in each circuit end to end.
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8.
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Replace the B88 passenger seat belt switch.
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Seat Belt Indicator Malfunction
2.
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Disconnect the harness connector at the P14 passenger air bag disable indicator.
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3.
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Test for less than 5 Ω between the ground circuit terminal 2 and ground.
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3.1.
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Disconnect the harness connector at the K36 SDM.
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3.2.
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Test for less than 2 Ω in each control circuit end to end.
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4.
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Connect a test lamp between the control circuit terminal 5 and ground.
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6.
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Command the Passenger Seat Belt Reminder ON and OFF with the scan tool. The test lamp should turn ON and OFF while changing between the commanded states.
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6.2.
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Disconnect the harness connector at the K36 SDM.
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6.4.
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Test for less than 1 V between the signal circuit and ground.
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6.1.
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Disconnect the harness connector at the K36 SDM.
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6.2.
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Test for infinite resistance between the seat belt switch signal circuit terminal 4 and ground.
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6.3.
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Test for less than 2 Ω in each control circuit end to end.
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7.
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Replace the P14 passenger air bag disable indicator.
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2.
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Disconnect the harness connector at the appropriate B88 passenger seat belt switch.
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3.
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B88 seat belt buckle in the open position.
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4.
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Test for infinite resistance between the signal circuit terminal A and the ground terminal B at the B88 passenger seat belt switch.
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5.
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Replace the B88 passenger seat belt switch.
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6.
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B88 seat belt switch in the closed position.
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7.
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Test for less than 2 Ω between the signal circuit terminal A and the ground terminal B at the B88 passenger seat belt switch.
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8.
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Replace the B88 passenger seat belt switch.
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Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.