DTC 024

DTC 024

DTC Descriptor

DTC 024

- PPS Ignition 1 Voltage Performance

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

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

The PPS detects ignition 1 voltage is less than 8 volts for 500 milliseconds.

Conditions for Setting the DTC

* The PPS detects the voltage at the passenger seat belt tension retractor sensor signal is less than 0.05 volt or greater than 4.5 volts for 500 milliseconds.
* The PPS detects the voltage at the passenger seat belt tension retractor sensor 5-volt reference is less than 4.5 volts or greater than 9.1 volts for 500 milliseconds.
* The PPS detects the amperage at the passenger seat belt tension retractor sensor low reference is 25 ma or greater 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 via GMLAN serial data.

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

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

1. 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

Ignition OFF, disconnect the PPS module connector. Refer to PPS replacement in Repairs Instructions for connector location.

2. Test the PPS ground circuit for an open or high resistance. Verify that an open or high resistance does not exist.

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

3. Test the PPS ignition 1 voltage circuit for a short to ground, an open, or high resistance. Verify that a short to ground, an open, or high resistance does not exist.

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

4. Reconnect all PPS components. Use the scan tool to clear all PPS DTCs. Refer to Passenger Presence System Flash Code Procedures. Rezero the PPS, refer to Passenger Presence System Rezeroing. Verify DTC 024 does not exist. Component Tests and General Diagnostics Programming and Relearning

• If DTC 024 reset replaced the PPS.

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

Control Module References for PPS replacement, setup, and programming