B0074
DTC B0074
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.
DTC Descriptors
DTC B0074 01
- Passenger Occupant Classification Sensor Circuit Short to Battery
DTC B0074 02
- Passenger Occupant Classification Sensor Circuit Short to Ground
DTC B0074 08
- Passenger Occupant Classification Sensor Circuit Signal Invalid
DTC B0074 11
- Passenger Occupant Classification Sensor Circuit Above Maximum Threshold
Circuit/System Description
The passenger presence system (PPS) uses a silicone filled sensor pad located underneath the passenger seat foam cushion and is connected by a hose clamp to a 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 is a 3-wire sensor consisting of a power, ground, and signal circuit. The PPS continually monitors itself and if a fault in this circuit occurs, a DTC will set. When the sensing and diagnostic module (SDM) 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 SDM through serial data communications that a PPS fault is present. The SDM will then 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 the voltage at the PPS sensor is less than 0.05 volt or greater than 4.5 volts for 500 milliseconds.
* The PPS detects the amperage at the PPS 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 serial data communications.
* The SDM disables the I/P module deployment loop.
* The PPS will turn ON the passenger air bag status OFF indicator.
* The SDM commands ON the AIR BAG warning lamp 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.
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 (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
* SIR/SRS Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information.
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 pressure sensor
* The PPS module
* The PPS pressure sensor wiring harness connector
* The PPS module wiring harness connector
1. Ignition OFF, Disconnect the PPS module harness connector.
2. Ignition OFF, test for less then 5 ohms of resistance between the PPS sensor ground circuit terminal D and ground.
• If greater then the specified range, test the circuit for an open/high resistance.
3. Ignition ON, verify a test lamp illuminates between the PPS B + circuit terminal A and ground.
• If the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance. if circuit tests normal, replace the PPS.
4. Reconnect all PPS components and perfrom the Passenger Presence System Preload Test (Programming and Relearning) .
5. Verify DTC B0074 is not set.
• If DTC B0074 is set, replace the PPS.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning)for PPS replacement, setup, and programming