Circuit Description
The inflatable restraint seat belt tension sensor is a 3-wire potentiometer mounted on the retractor or buckle side of the seat belt and provides an input to the passenger presence system (PPS). When an infant car seat is properly restrained on the front passenger seat, the seat belt is tightly secured through the car seat. The seat belt pulls on the tension sensor and changes the voltage signal to the PPS module. The PPS monitors the seat belt tension sensor circuit and if a fault is detected, DTC 023 will be set. When the PPS detects this DTC within the PPS, it will notify the customer of the enable/disable status by turning ON the OFF indicator on the PASSENGER AIR BAG ON/OFF indicators. Then the PPS will communicate to the sensing and diagnostic module (SDM) through a non-class 2 communications circuit that a PPS fault is present. The SDM will then turn the AIR BAG indicator ON, and set DTC B0092 indicating a problem within the PPS and will suppress the deployment of the instrument panel (I/P) module.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC 023 Seat Belt Tension Sensor Circuit Out of Range
Conditions for Running the DTC
Ignition 1 voltage is within the normal operating voltage range.
Conditions for Setting the DTC
| • | The PPS detects the voltage at the passenger seat belt tension retractor sensor signal is less than 0.05 volt or greater than 4.5 volts for 500 milliseconds. |
| • | The PPS detects the voltage at the passenger seat belt tension retractor sensor 5-volt reference is less than 4.5 volts or greater than 9.1 volts for 500 milliseconds. |
| • | The PPS detects the amperage at the passenger seat belt tension retractor sensor low reference is 25 ma or greater for 500 milliseconds. |
Action Taken When the DTC Sets
| • | The PPS will set a DTC 023, then communicate with the SDM via non-class 2 circuit. |
| • | The SDM will set DTC B0092. |
| • | The SDM disables the I/P module deployment loop. |
| • | The PPS will turn ON the passenger air bag status OFF indicator. |
| • | The SDM commands the AIR BAG indicator ON via class 2 serial data. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | You issue a scan tool CLEAR DTCs command. |
| • | A history DTC will clear once 255 malfunction-free ignition cycles have occurred. |
Diagnostic Aids
The following can cause an intermittent condition:
| • | A short between the passenger seat belt tension retractor sensor signal, 5-volt reference, and low reference circuits |
| • | An open or high resistance between the passenger seat belt tension retractor sensor signal, 5-volt reference, and low reference circuits |
| • | Inspect the passenger seat belt tension retractor sensor signal, 5-volt reference, and low reference circuits carefully for cutting and/or chafing. |
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. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step tests for a short to ground, a high resistance, or an open in the seat belt tension retractor sensor signal circuit.
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This step tests for a short to ground, a high resistance, or an open in the seat belt tension retractor sensor 5-volt reference circuit.
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This step tests for a short to ground, a high resistance, or an open in the seat belt tension retractor sensor low reference circuit.
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This step tests for a short to voltage in the seat belt tension retractor sensor signal circuit.
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This step tests the seat belt tension retractor sensor signal circuit input voltage range.
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This step tests for a short to voltage in the seat belt tension retractor sensor 5-volt reference circuit.
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This step tests for a short to voltage in the seat belt tension retractor sensor low reference circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the seat belt tension retractor sensor terminals or harness connector exhibit any signs of damage or corrosion? | -- | Go to Step 3 | Go to Step 4 |
3 |
Did you complete the replacement? | -- | Go to Step 15 | -- |
4 |
Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 5 |
Test the seat belt tension retractor sensor signal circuit for high resistance, an open, or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 6 | |
Test the seat belt tension retractor sensor 5-volt reference circuit for high resistance, an open, or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 7 | |
Test the seat belt tension retractor sensor low reference circuit for high resistance, an open, or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 8 | |
Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 9 | |
Test the seat belt tension retractor sensor signal circuit input voltage. Refer to Circuit Testing and Wiring Repairs . Does the voltage measure within the specified range ? | 0.05-4.5 V | Go to Step 10 | Go to Step 12 | |
Test the seat belt tension retractor sensor 5-volt reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 11 | |
Test the seat belt tension retractor sensor low reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 | |
12 |
Important: The seat belt tension retractor sensor is not serviced separately. Replace the seat belt tension retractor sensor. Refer to Seat Belt Retractor Replacement - Right Front . Did you complete the replacement? | -- | Go to Step 13 | -- |
13 |
Does the DTC reset? | -- | Go to Step 14 | System OK |
14 | Replace the PPS. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 15 | -- |
15 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
