GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The inflatable restraint passenger presence system (PPS) continuously monitors itself for critical faults. If the PPS determines that there is a communication fault or battery voltage has fallen below a threshold causing a communication fault, the PPS will set DTC 036, turn the passenger air bag status indicator to OFF. Then the PPS will try to communicate with 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 to 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 036 Communication Fault

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

    • The PPS has lost communications with the SDM.
    • The PPS receives incorrect messages.
    • The SDM has lost or receive no communications with the PPS.
    • Battery voltage outside the range of 8-18 volts.

Action Taken When the DTC Sets

    • The PPS will set a DTC 036, then communicate with the SDM via non class 2 circuit.
    • The SDM will set DTC B0092.
    • The SDM disables the I/P 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

This fault indicates that there is either a communication or battery voltage problem. If this DTC sets intermittently, check the power, ground and communication circuits. Refer to Testing for Intermittent Conditions and Poor Connections.

Test Description

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

  1. This step is requesting the PPS to flash internal DTCs, checking to see if DTC 036 is current.

  2. Test the occupant sensor serial data circuit for a short to ground, a high resistance, or an open.

  3. Test the occupant sensor serial data circuit for a short to voltage.

Step

Action

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

Go to Diagnostic System Check - Vehicle

2

  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool, request the passenger presence system (PPS) to flash DTCs. Refer to Passenger Presence System Flash Code Procedures .

Does the PPS indicate that DTC 036 is current?

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Disconnect the PPS module connector. Refer to Control Module References for replacement, setup, and programming.
  3. Inspect the PPS module terminals and harness connector for damage or corrosion.

Does the PPS module terminals or harness connector exhibit any signs of damage or corrosion?

Go to Step 4

Go to Step 5

4

  1. If the PPS module terminals are damaged, replace the PPS. Refer to Control Module References for replacement, setup, and programming.
  2. If the PPS harness connector is damaged, replace the connector. Refer to Connector Repairs.

Did you complete the replacement?

Go to Step 10

--

5

  1. Disconnect the main seat harness connector located under the RF seat. Refer to Power Seat Connector End Views.
  2. Inspect both halves of the connector for corrosion or damage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

  1. Disconnect the sensing and diagnostic module (SDM) connector. Refer to Control Module References for replacement, setup, and programming.
  2. Inspect the SDM connector for corrosion or damage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.

Did you find and correct the condition?

Go to Step 10

Go to Step 7

7

Test the occupant sensor serial data circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

Go to Step 10

Go to Step 8

8

  1. Turn ON the ignition, with the engine OFF.
  2. Test the occupant sensor serial data circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

9

  1. Turn OFF the ignition.
  2. Important: The PPS, heated seat element, and seat bottom cushion is only serviced as a complete kit.

  3. Replace the PPS. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

10

  1. Reconnect all SIR and PPS system components.
  2. Verify that all components, connectors, and connector position assurances (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 11

System OK

11

Replace the SDM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

--

12

  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 2

System OK