For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC 064: Communication/ID Performance

### Circuit/System Description

The passenger presence system (PPS) communicates over a non GMLAN communication circuit to the inflatable restraint sensing and diagnostic module (SDM). When the ignition is turned ON, the PPS module will check to make sure the PPS verification ID matches that stored in the SDM. If the SDM cannot communicate with the PPS, the SDM will set a DTC and request the instrument panel cluster (IPC) to turn the AIR BAG indicator ON. If the SDM can communicate to the PPS but the verification ID does not match, the PPS will set DTC 033 and notify the SDM that a fault has occurred. The SDM will then set DTC B0081 indicating a problem within the PPS and will suppress the deployment of the instrument panel (I/P) module and then turn the AIR BAG indicator ON.

### Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

### Conditions for Setting the DTC

• | The PPS has lost communications with the SDM.

• | The PPS verification ID does not match the ID that is stored in the SDM.

### Action Taken When the DTC Sets

• | The PPS will set a DTC, and then communicate with the SDM via non GMLAN circuit.

• | The SDM will set DTC B0081.

• | 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.

### Conditions for Clearing the DTC

• | The condition for setting the DTC no longer exists.

• | A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

### Diagnostic Aids

The SDM has received an incorrect PPS verification ID. The SDM will continue to request the verification ID from the PPS for 5 seconds. If the SDM does not communicate or receive the correct verification ID from the PPS within 5 seconds, the SDM will set DTC B0081 as current.

### Reference Information

#### Schematic Reference

SIR Schematics

#### Connector End View Reference

SIR Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### Circuit/System Testing

Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

• | The PPS module

• | The SDM module

• | The PPS wiring harness connector

• | The SDM wiring harness connector

1. Ignition ON, use the scan tool. Go to the PPS menu, then retrieve the DTCs. Refer to Passenger Presence System Flash Code Procedures . Verify DTC 064 is set.
2. Ignition OFF, disconnect the PPS module connector.
3. Remove the SDM connector.
4. Test the PPS communication circuit between the SDM and the PPS for a short to ground, a high resistance, or an open. Verify short to ground, a high resistance, or an open exist.

⇒ | If any of the above conditions are found make the appropriate repair.

5. Replace the PPS.
6. Use the scan tool to clear all PPS DTCs. Refer to Passenger Presence System Flash Code Procedures . Verify DTC 064 does not exist.

⇒ | If DTC 064 reset replaced the SDM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | SIR/SRS Wiring Repairs

• | Control Module References for PPS or SDM replacement, setup, and programming