GM Service Manual Online
For 1990-2009 cars only

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 063: PPS Out of Calibration

Circuit/System 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 instrument panel (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 illuminating either the ON of OFF indicator on the PASSENGER AIR BAG ON/OFF indicators. The PPS monitors itself for faults and will set flash DTCs if a fault is detected. The PPS will also notify the SDM of a fault. The SDM will respond by setting DTC B0092 and requesting the instrument panel cluster (IPC) to illuminate the AIR BAG indicator. The PPS will set DTC 063 as an indication that the PPS is out of calibration. The PPS is not capable of being calibrated at the service level, the PPS must be replaced.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

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 PPS will set a DTC, and then communicate with the SDM.
    • The SDM will set DTC B0081.
    • The SDM disables the instrument panel (I/P) module deployment loop.
    • The PPS will illuminate the passenger air bad status OFF indicator.
    • The SDM requests the IPC to illuminate the AIR BAG indicator.

Conditions for Clearing the DTC

DTC 063 is an indication that the PPS is out of calibration. You cannot recalibrate the PPS. Replace the PPS after following the instructions in the diagnostic table below.

Diagnostic Aids

The presence of current or history DTC while attempting to rezero the PPS will cause the PPS module to set DTC 063. Verify that all SIR and PPS DTC have been cleared before rezeroing the PPS.

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

SIR System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

Ignition ON, clear all SIR and PPS DTCs. Refer to Passenger Presence System Flash Code Procedures. Rezero the PPS using the Control Module References. Verify DTC 063 does not reset.

If DTC 063 resets, replace the PPS module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  SIR/SRS Wiring Repairs
    •  Control Module References for PPS replacement, setup, and programming