GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 GMC C Sierra - 2WD 🢒 Restraints 🢒 SIR 🢒 DTC 023

Circuit Description

The inflatable restraint seat belt tension retractor 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 retractor 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 retractor sensor and the PPS pressure sensor to determine if the I/P module should be suppressed or enabled. The PPS monitors the seat belt tension retractor sensor circuits and sets diagnostic trouble code (DTC) 023 if a fault is detected.

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 passenger seat belt tension retractor sensor signal is less than 0.05 volts or greater than 4.5 volts for 500 milliseconds.
    • The PPS detects the voltage at 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 passenger seat belt tension retractor sensor low reference is 25 ma or greater for 500 milliseconds.

Action Taken When the DTC Sets
    • The SDM disables the I/P module 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 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

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. Tests for a short to ground, a high resistance, or an open in the seat belt tension retractor sensor signal circuit.

    2.

  2. Tests for a short to ground, a high resistance, or an open in the seat belt tension retractor sensor 5-volt reference circuit.

    3.

  3. Tests for a short to ground, a high resistance, or an open in the seat belt tension retractor sensor low reference circuit.

    4.

  4. Tests for a short to voltage in the seat belt tension retractor sensor signal circuit.

    5.

  5. Tests the seat belt tension retractor sensor signal circuit input voltage range.

    6.

  6. Tests for a short to voltage in the seat belt tension retractor sensor 5-volt reference circuit.

    7.

  7. 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 - SIR?

--

Go to Step 2

Go to Diagnostic System Check - SIR

2
  1. Turn OFF the ignition.
  2. Disconnect the seat belt tension retractor sensor connector.
  3. Inspect the seat belt tension retractor sensor terminals and harness connector for damage or corrosion.

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
  1. If the seat belt tension retractor sensor terminals are damaged, replace the seat belt tension retractor sensor. Refer to Seat Belt Retractor Replacement - Right Front .
  2. If the seat belt tension retractor sensor harness connector is damaged, replace the connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the replacement?

--

Go to Step 15

--

4
  1. Disconnect the PPS module connector.
  2. Inspect the PPS module connector for corrosion or damage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 5

5

Test the seat belt tension retractor sensor signal circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 6

6

Test the seat belt tension retractor sensor 5 volt reference circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 7

7

Test the seat belt tension retractor sensor low reference circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 8

8

  1. Turn ON the ignition, with the engine OFF.
  2. Test the seat belt tension retractor sensor signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 9

9

Test the seat belt tension retractor sensor signal circuit input voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Does the voltage measure within the specified range ?

0.05-4.5 V

Go to Step 10

Go to Step 12

10

Test the seat belt tension retractor sensor 5-volt reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 11

11

Test the seat belt tension retractor sensor low reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

12

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
  1. Reconnect all SIR and PPS system components.
  2. Verify that all components, connectors, and CPAs are properly mounted.
  3. Use the scan tool in order to clear the SIR and PPS DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 14

System OK

14

Important: The PPS is a calibrated system. The PPS must be rezeroed after replacement.

Replace the PPS. Refer to Inflatable Restraint Passenger Presence System Replacement - Front .

Did you complete the replacement?

--

Go to Step 15

--

15
  1. Reconnect all SIR and PPS system components.
  2. Verify that all components, connectors and CPAs are properly mounted.
  3. Use the scan tool in order to clear the SIR and PPS DTCs.
  4. Rezero the PPS. Refer to Passenger Presence System Rezeroing .
  5. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK