B1797

DTC B1797

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC B1797
- Passenger Presence System Calibration

Circuit/System Description

This DTC identifies a malfunction within the passenger presence system (PPS). If the sensing and diagnostic module (SDM) detects a malfunction within the PPS module, a DTC will be set.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

* Calibration has failed.
* Calibration performed with conditions for calibration not satisfied.

Action Taken When the DTC Sets

* The SDM commands the AIR BAG indicator ON.
* The SIR System is disabled and no deployments are allowed.

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.

Reference Information
Schematic Reference

SIR Schematics ([1][2]Air Bag Systems)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

SIR System Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Connector Repairs (Connector Repairs)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information.

Circuit/System Testing

Important: Refer to SIR Service Precautions (Technician Safety Information).


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


* The front end sensor

* The SDM module

* The front end sensor wiring harness connector

* The SDM wiring harness connector


1. Connect all SIR components. Ignition ON, with a scan tool clear and check for DTCs.

• If the DTC is not current, perform PPS rezeroing procedure.

2. Using a scan tool, observe the following parameters:

* Pressure sensor output, 0-2
* Thermistor temperature output, 3-40°C (37-104°F)
* Current DTCs, 0
* History DTCs, 0

• If the parameters are not as specified, replace the PPS seat sensor.

• If the parameters are as specified, perform PPS rezeroing procedure.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Inflatable Restraint Front End Sensor Replacement (Inflatable Restraint Front End Sensor Replacement)
* Inflatable Restraint Side Impact Sensor Replacement (Front) (Inflatable Restraint Side Impact Sensor Replacement (Front))Inflatable Restraint Side Impact Sensor Replacement (Rear) (Inflatable Restraint Side Impact Sensor Replacement (Rear))
* SIR/SRS Wiring Repairs (SIR/SRS Wiring Repairs)
* Control Module References (Programming and Relearning) for SDM replacement, setup, and programming