DTC B0072 or B0073
Diagnostic Instructions
DTC Descriptors
DTC B0072 01
Driver Seat Belt Switch Circuit Short to Battery
DTC B0072 02
Driver Seat Belt Switch Circuit Short to Ground
DTC B0072 04
Driver Seat Belt Switch Circuit Open
DTC B0072 05
Driver Seat Belt Switch Circuit High Voltage/Open
DTC B0072 06
Driver Seat Belt Switch Circuit Low Voltage/Open
DTC B0072 08
Driver Seat Belt Switch Circuit Performance - Signal Invalid
DTC B0072 0B
Driver Seat Belt Switch Circuit High Current
DTC B0072 0C
Driver Seat Belt Switch Circuit Low Current
DTC B0073 01
Passenger Seat Belt Switch Circuit Short to Battery
DTC B0073 02
Passenger Seat Belt Switch Circuit Short to Ground
DTC B0073 04
Passenger Seat Belt Switch Circuit Open
DTC B0073 05
Passenger Seat Belt Switch Circuit High Voltage/Open
DTC B0073 06
Passenger Seat Belt Switch Circuit Low Voltage/Open
DTC B0073 08
Passenger Seat Belt Switch Circuit Performance - Signal Invalid
DTC B0073 0B
Passenger Seat Belt Switch Circuit High Current
DTC B0073 0C
Passenger Seat Belt Switch Circuit Low Current
Diagnostic Fault Information
Circuit/System Description
The inflatable restraint seat belt buckle switch is within the seat belt buckle and provides an input to the inflatable restraint sensing and diagnostic module (SDM). The inflatable restraint sensing and diagnostic module supplies a low reference circuit and a seat belt switch signal circuit to determine a buckled or unbuckled condition. The inflatable restraint sensing and diagnostic module monitors the seat belt switch circuits and if a fault is detected a DTC will be set.
Conditions for Running the DTC
Ignition voltage is between 9 - 16 V.
Conditions for Setting the DTC
B0072 01 or B0073 01
The seat belt switch circuit is shorted to voltage.
B0072 02 or B0073 02
The seat belt switch circuit is shorted to ground.
B0072 04 or B0073 03
The seat belt switch circuit is open.
B0072 05 or B0073 05
The seat belt switch circuit is shorted to voltage or open.
B0072 06 or B0073 06
The seat belt switch circuit is shorted to ground or open.
B0072 08 or B0073 08
The seat belt switch signal is invalid.
B0072 0B or B0073 0B
The seat belt switch signal is above threshold.
B0072 0C or B0073 0C
The seat belt switch signal is below threshold.
Action Taken When the DTC Sets
The inflatable restraint sensing and diagnostic module will store a DTC and illuminate the air bag indicator in the instrument cluster.
Conditions for Clearing the DTC
The condition for setting the DTC no longer exists.
Reference Information
Schematic Reference
Seat Belt Wiring Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEWS - INDEX
Description and Operation
Supplemental Inflatable Restraint System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information.
Circuit/System Verification
1. Ignition ON.
2. Verify the appropriate scan tool Seat Belt Status parameter changes between Buckled and Unbuckled when the seat belt is buckled and unbuckled.
Refer to Circuit/System Testing.
3. All OK.
Circuit/System Testing
NOTE: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.
1. Ignition OFF. Scan tool disconnected. Disconnect the harness connector at the appropriate Seat Belt Buckle. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 5 Ω between the low reference circuit terminal 2 and ground.
3. Ignition ON.
4. Verify the appropriate scan tool Seat Belt Status parameter is Buckled.
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2.
6. Verify the appropriate scan tool Seat Belt Status parameter is Unbuckled.
7. Test or replace the Seat Belt Buckle.
Component Testing
1. Ignition OFF. Scan tool disconnected. Disconnect the harness connector at the appropriate Seat Belt Buckle. It may take up to 2 min for all vehicle systems to power down.
2. Test for infinite resistance between the signal terminal 1 and the low reference terminal 2.
Replace the B153 Seat Belt Buckle.
3. Insert the seat belt into the buckle.
4. Test for less than 5 Ω between the signal terminal 1 and the low reference terminal 2.
Replace the Seat Belt Buckle.
5. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
DTC B0075-B0077
Diagnostic Instructions
DTC Descriptors
DTC B0075
Left Rear Seat Belt Switch Circuit
DTC B0076
Right Rear Seat Belt Switch Circuit
DTC B0077
Center Rear Seat Belt Switch Circuit
For symptom byte information refer to Symptom Byte List.
Diagnostic Fault Information
Circuit/System Description
The inflatable restraint seat belt buckle switch is within the seat belt buckle and provides an input to the Inflatable Restraint Sensing and Diagnostic Module (SDM). The Inflatable Restraint Sensing and Diagnostic Module supplies a low reference circuit and a seat belt switch signal circuit to determine a buckled or unbuckled condition. The Inflatable Restraint Sensing and Diagnostic Module monitors the seat belt switch circuits and if a fault is detected a DTC will be set.
Conditions for Running the DTC
Ignition voltage is between 9 - 16 V.
Conditions for Setting the DTC
B0075 01, B0076 01, or B0077 01
The seat belt switch circuit is shorted to voltage.
B0075 02, B0076 02, or B0077 02
The seat belt switch circuit is shorted to ground.
B0075 04, B0076 04, or B0077 04
The seat belt switch circuit is open.
B0075 05, B0076 05, or B0077 05
The seat belt switch circuit is shorted to voltage or open.
B0075 06, B0076 06, or B0077 06
The seat belt switch circuit is shorted to ground or open.
B0075 08, B0076 08, or B0077 08
The seat belt switch signal is invalid.
B0075 0B, B0076 0B, or B0077 0B
The seat belt switch signal is above threshold.
B0075 0C, B0076 0C, or B0077 0C
The seat belt switch signal is below threshold.
Action Taken When the DTC Sets
The Inflatable Restraint Sensing and Diagnostic Module will store a DTC and illuminate the Air Bag indicator in the instrument cluster.
Conditions for Clearing the DTC
The condition for setting the DTC no longer exists.
Reference Information
Schematic Reference
SIR Wiring Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEWS - INDEX
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
1. Ignition ON.
2. Verify the appropriate scan tool Seat Belt Status parameter changes between Buckled and Unbuckled when the seat belt is buckled and unbuckled.
Refer to Circuit/System Testing.
3. All OK.
Circuit/System Testing
NOTE: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.
1. Ignition OFF, disconnect the harness connector at the appropriate B88 seat belt switch.
2. Test for less than 5 Ω between the low reference circuit terminal 2 and ground.
3. Ignition ON.
4. Verify the appropriate scan tool Seat Belt Status parameter is Buckled.
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2.
6. Verify the appropriate scan tool Seat Belt Status parameter is Unbuckled.
7. Test or replace the B88 Seat Belt Switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the B88 Seat Belt Switch.
2. Test for infinite resistance between the signal terminal 1 and the low reference terminal 2.
Replace the B88 Seat Belt Switch.
3. Insert the seat belt into the buckle.
4. Test for less than 5 Ω between the signal terminal 1 and the low reference terminal 2.
Replace the B88 Seat Belt Switch.
5. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Symptoms - Seat Belts
NOTE: Review the seat belt system description and operation in order to familiarize yourself with the system and how it functions.
Visual/Physical Inspection
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections.
Symptom List
Refer to the following symptom diagnostic procedure in order to diagnose the symptom:
SEAT BELT INDICATOR MALFUNCTION - DRIVER
Diagnostic Instructions
Diagnostic Fault Information
1. Seat Belt Indicator Always Illuminated
2. Seat Belt Indicator Inoperative
Circuit/System Description
The driver 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 driver seat belt via serial data to the instrument cluster. After receiving the message, the instrument cluster controls the illumination of the driver seat belt indicator.
Reference Information
Schematic Reference
Connector End View Reference
COMPONENT CONNECTOR END VIEWS - INDEX
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
1. Command the instrument cluster all indicators ON and OFF with a scan tool. The driver seat belt indicator should turn ON and OFF as commanded.
Replace the P16 instrument cluster.
2. Monitor the scan tool Driver Seat Belt Switch parameter while buckling and unbuckling the seat belt. The parameter should display Buckled and Unbuckled when changing seat belt states.
Refer to Circuit/System Testing.
3. All OK.
Circuit/System Testing
NOTE: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.
1. Ignition OFF.
2. Disconnect the harness connector at the B88 seat belt switch.
3. Test for less than 10 Ω between the low reference circuit terminal 1 and ground.
4. Ignition ON.
5. Verify the scan tool Driver Seat Belt Status parameter displays Buckled.
6. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1.
7. Verify the scan tool Driver Seat Belt Status parameter displays Unbuckled.
8. Replace the B88 seat belt switch.
Component Testing
1. Ignition OFF.
2. Disconnect the harness connector at the B88 seat belt switch.
3. B88 seat belt switch in the open position.
4. Test for infinite resistance between the signal circuit terminal 2 and the low reference terminal 1 at the B88 seat belt switch.
Replace the B88 seat belt switch.
5. B88 seat belt switch in the closed position.
6. Test for less than 1 Ω between the signal circuit terminal 2 and the low reference terminal 1 at the B88 seat belt switch.
Replace the B88 seat belt switch.
7. All OK.
Repair Instructions
Seat Belt Indicator Malfunction - Passenger
Diagnostic Instructions
Diagnostic Fault Information
1. Indicator will remain ON with seat belt buckled.
2. Indicator will illuminate only for the bulb check.
3. Indicator will not illuminate.
4. Indicator always ON.
Circuit/System Description
When an individual is sitting in the passenger seat the passenger presence sensor detects the individual.
A signal to the inflatable restraint sensing and diagnostic module indicates a person is in the passenger seat. The inflatable restraint sensing and diagnostic module will turn the passenger seat belt indicator on.
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 inflatable restraint sensing and diagnostic module sends the status of the passenger seat belt via a hard wire to the passenger air bag disable switch. After receiving the message, the passenger air bag disable switch controls the illumination of the passenger seat belt indicator.
Diagnostic Aids
Objects on the passenger seat can cause the passenger seat belt reminder to be commanded on.
Depending on the sensing technology used, a conductive object (computers, MP3 players, cell phones, diagnostic scan tool, wires, a hand, etc.) placed on the passenger seat may cause the passenger presence module to command the passenger air bag indicator ON and/or command the passenger seat belt indicator ON. The fasten seat belt chime will also sound.
Reference Information
Schematic Reference
Seat Belt Wiring Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEWS - INDEX
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
1. Ignition ON.
2. Verify the passenger seat belt indicator turns ON and OFF when performing the Passenger Seat Belt Reminder Indicator On/Off Control Function with a scan tool.
Refer to Circuit/System Testing - Seat Belt Indicator Malfunction.
3. Verify the scan tool Passenger Seat Belt Status parameter changes between Buckled and Unbuckled when buckling and unbuckling the seat belt.
Refer to Circuit/System Testing - Seat Belt Switch Malfunction.
4. All OK.
Circuit/System Testing
Seat Belt Switch Malfunction
NOTE: When removing connectors inspect for damage or corrosion.
Damage or corrosion in the following requires repair or replacement of the affected component/connector.
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B153 Seat Belt Buckle - Passenger. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 5 Ω between the low reference circuit terminal 1 and ground.
3. Ignition ON.
4. Verify the scan tool Passenger Seat Belt Status parameter is Buckled.
5. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the ground circuit terminal 1.
6. Verify the scan tool Passenger Seat Belt Status parameter is Unbuckled.
7. Ignition OFF, connect all harness connectors. Ignition ON.
8. Verify the scan tool Passenger Seat Belt Status parameter changes between Buckled and Unbuckled when buckling and unbuckling the seat belt.
Test or replace the B153 Seat Belt Buckle - Passenger.
9. All OK.
Seat Belt Indicator Malfunction
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the P14 Passenger Air Bag Disable Indicator. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 20 Ω between the ground circuit terminal 3 and ground.
3. Test for 3-7 V between terminal 6 and ground when commanding the Passenger Seat Belt Reminder On with a scan tool.
4. Test for less than 1 V between terminal 6 and ground when commanding the Passenger Seat Belt Reminder OFF with a scan tool.
Replace the K36 Inflatable Restraint Sensing and Diagnostic Module
5. Test or replace the P14 Passenger Air Bag Disable Indicator.
Component Testing
1. Ignition OFF, disconnect the harness connector at the B153 Seat Belt Buckle - Passenger.
2. Buckle the passenger seat belt.
3. Test for infinite resistance between the signal circuit terminal 2 and the low reference circuit terminal 1.
Replace the B153 Seat Belt Buckle - Passenger.
4. B88 seat belt switch in the unbuckled position.
5. Test for less than 2 Ω between the signal circuit terminal 2 and the low reference terminal 1.
Replace the B153 Seat Belt Buckle - Passenger.
6. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair