Circuit Description
The inflatable restraint seat belt tension sensor is used to enhance the passenger presence system (PPS) when an infant car seat is properly restrained on the front outboard passenger seat. The seat belt tension sensor is a 3-wire potentiometer mounted on the lower seat belt anchor and provides an input to the PPS module. When an infant car seat is properly restrained on the front passenger seat, the seat belt is tightly secured through the infant car seat. The seat belt pulls on the tension sensor and changes the voltage signal to the PPS module. The PPS module uses the voltage signal to help determine if a tightly belted infant car seat is installed. The PPS uses the inputs from the seat belt tension sensor and the PPS pressure sensor to determine if the instrument panel module (IPM) should be suppressed or enabled. The PPS monitors the seat belt tension sensor circuits and sets DTC 023 if a fault is detected.
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 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 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 sensor low reference is 25 mA or greater for 500 milliseconds. |
Action Taken When the DTC Sets
| • | The sensing and diagnostic module (SDM) disables the IPM deployment loop. |
| • | 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 sensor signal, 5-volt reference, and low reference circuits |
| • | An open or high resistance between the passenger seat belt tension sensor signal, 5-volt reference, and low reference circuits |
| • | Inspect the passenger seat belt tension sensor signal, 5-volt reference, and low reference circuits carefully for cutting and/or chafing. |
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 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 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 sensor low reference circuit.
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This step tests for a short to voltage in the seat belt tension sensor signal circuit.
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This step tests the seat belt tension sensor signal circuit input voltage range.
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This step tests for a short to voltage in the seat belt tension sensor 5-volt reference circuit.
-
This step tests for a short to voltage in the seat belt tension 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 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 sensor signal circuit for the following:
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 sensor 5-volt reference circuit for the following:
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 sensor low reference circuit for the following:
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 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 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 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 | Replace the seat belt tension sensor. Refer to Driver or Passenger Seat Belt Buckle Replacement. 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 | ||||||
