DTC 024

DTC 024

Diagnostic Instructions

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

DTC Descriptor

DTC 024
- PPS Ignition 1 Voltage Performance

Circuit/System Description

The passenger presence system (PPS) module has an ignition 1 voltage input. The PPS continually monitors itself for faults. If the voltage on this circuit falls below a certain threshold, the PPS will set DTC 024. When the PPS detects this DTC within the PPS it will notify the customer of the enable/disable status by turning ON the OFF indicator on the PASSENGER AIR BAG ON/OFF indicators. Then the PPS will communicate to the sensing and diagnostic module (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 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 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 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 PPS will set DTC 024 as a history code only, when the ignition voltage has fallen below 8 volts. This is a normal condition for DTC 024 and it should be diagnosed as a current DTC.

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 PPS wiring harness connector

1. Ignition OFF, disconnect the harness connector at the PPS module.
2. Ignition OFF, test for less than 1.0 ohm between the ground circuit terminal 5 and ground.

• If not within the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PPS module.

3. Ignition ON, engine ON, verify that a test lamp illuminates between the ignition 1 voltage circuit terminal 9 and ground.

• If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance.

4. If all circuits test normal, test or replace the PPS module.

Repair Instructions

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

* SIR/SRS Wiring Repairs