GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 GMC C Sierra - 2WD 🢒 Restraints 🢒 SIR 🢒 DTC 024

Circuit Description

The inflatable restraint passenger presence system (PPS) is used to monitor the weight of an occupant on the front outboard passenger seat and communicate the status to the sensing and diagnostic module (SDM) whether to enable or suppress the deployment of the I/P module. The PPS consist of an electronic control module, silicone filled sensor pad, pressure sensor, seat belt tension retractor sensor, wiring harness, and PASSENGER AIR BAG ON/OFF indicators. The silicone filled sensor pad is located under the passenger seat foam cushion and is connected by a hose clamped to the pressure sensor. The weight of the occupant sitting in the front passenger seat is measured as a pressure change within the bladder by the pressure sensor. The pressure sensor sends a voltage signal to the PPS module. If the pressure from the occupant's weight is less than a specified value, the PPS module will send a suppress signal to the SDM to disable the I/P module. If the pressure from the occupant's weight is higher than a specified value, the PPS module will send an enable signal to the SDM to enable the I/P module. The PPS module will notify the customer of the enable/disable status by turning on one of the PASSENGER AIR BAG ON/OFF indicators located on the rear view mirror. The PPS monitors itself for faults and will set flash diagnostic trouble codes (DTCs) if a fault is detected. The PPS will also notify the SDM of a fault. The SDM will respond by setting either DTC B0092 or B0098 and requesting the instrument panel cluster (IPC) to turn the AIR BAG indicator ON.

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The PPS detects ignition 1 voltage is less than 8 volts 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 in the ignition 1 voltage circuit between the PPS module and the body relay block
    • An open or high resistance in the ignition 1 voltage circuit between the PPS module and the body relay block

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

The PPS will set DTC 024 when the ignition voltage has fallen bellow 8 volts. The PPS will set DTC 024 as a history code only. This is a normal condition for DTC 024 and it should be diagnosed as a current DTC.

Test Description

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

  1. Inspects the PPS module connector.

    2.

  2. Inspects the main seat harness connector.

    3.

  3. Tests the PPS ground circuit for an open or high resistance.

    4.

  4. Tests the PPS ignition 1 voltage circuit for a short to ground, an open, or high resistance.

Step

Action

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 PPS module connector.
  3. 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 7

Go to Step 3

3

  1. Disconnect the main seat harness connector located under the RF seat. Refer to Power Seat Connector End Views in Seats.
  2. Inspect both halves of the 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 7

Go to Step 4

4

Test the PPS ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 5

5

Test the PPS ignition 1 voltage circuit for a short to ground, an open, or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 6

6

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 7

--

7
  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