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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 STS 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 DTC 1051

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 1051: PPS Initialization/Preload Fault

Circuit/System Description

The passenger presence system (PPS) is used to monitor the pressure profile of any occupant that is sitting in the front outboard passenger seat and communicates the profile classification to the sensing and diagnostic module (SDM). The SDM will either enable or suppress the deployment of the instrument panel (I/P) module based on the profile classification of the occupant. If the PPS has been replaced the new PPS must run a preload test on the completed serviced seat before that vehicle is released back to the customer. This test assures that completed serviced seat does not add any pressure to the seat surface that could influence the pressure profile of any occupant that is sitting in the seat. This test must be performed on an empty seat. When a new PPS is installed a DTC will set indicating that a preload test needs to be preformed. If the PPS detects any preload DTC within the PPS, then the PPS will communicate to the SDM through a non GMLAN communications circuit that a PPS fault is present. The SDM will then set DTC B0081 indicating a problem within the PPS and will suppress the deployment of the 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 will set this DTC when replaced.

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 via serial data communications.

Conditions for Clearing the DTC
    • The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
    • A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

Diagnostic Aids

When a new PPS and seat bottom foam has been installed, a DTC 1051 will be set indicating that the preload test procedure must be run.

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
  1. Ignition ON, use the scan tool. Go to the PPS menu, then retrieve the DTCs. Refer to Passenger Presence System Displaying Code Procedure . Verify DTC 1051 does not set.
    2. ⇒If DTC 1051 is set as current, refer to Passenger Presence System Preload Test .
  2. Verify DTC 1052, 1053, 1054, or 1055 is set as current.
    3. ⇒If DTC 1052, 1053, 1054, or 1055 is set refer to DTC 1052, 1053, 1054, or 1055 .
  3. Use the scan tool and perform Passenger Presence System Preload Test , and then request codes. Verify that there is no preload DTC exist.

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