DTC 024

DTC 024

CIRCUIT DESCRIPTION
The inflatable restraint passenger presence system (PPS) is used to monitor the weight of an occupant on the front outboard passenger seat and communicate the status to the sensing and diagnostic module (SDM) whether to enable or suppress the deployment of the instrument panel (I/P) module. The PPS consist of an electronic control module, silicone filled sensor pad, pressure sensor, seat belt tension retractor sensor, wiring harness, and PASSENGER AIR BAG ON/OFF indicators. The silicone filled sensor pad is located under the passenger seat foam cushion and is connected by a hose clamped to the 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 sends a voltage signal to the PPS module. If the pressure from the occupant's weight is less than a specified value, the PPS module will send a suppress signal to the SDM to disable the I/P module. If the pressure from the occupant's weight is higher than a specified value, the PPS module will send an enable signal to the SDM to enable the I/P module. The PPS module will notify the customer of the enable/disable status by turning on one of the PASSENGER AIR BAG ON/OFF indicators located on the rearview mirror. The PPS monitors itself for faults and will set flash DTCs if a fault is detected. The PPS will also notify the SDM of a fault. The SDM will respond by setting either DTC B0092 or B0098 and requesting the instrument panel cluster (IPC) to turn the AIR BAG indicator ON.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC 024 PPS Ignition 1 Voltage Performance

CONDITIONS FOR RUNNING THE DTC
Ignition 1 voltage is within the normal operating voltage range.

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 SDM disables the I/P module deployment loop.
- The SDM commands the AIR BAG indicator ON via class 2 serial data.

CONDITIONS FOR CLEARING THE DTC
- The condition responsible for setting the DTC no longer exists.
- You issue a scan tool CLEAR DTCs command.
- A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

DIAGNOSTIC AIDS
The following can cause an intermittent condition:
- A short in the ignition 1 voltage circuit between the PPS module and the body relay block
- An open or high resistance in the ignition 1 voltage circuit between the PPS module and the body relay block

The PPS will set DTC 024 when the ignition voltage has fallen below 8 volts. The PPS will set DTC 024 as a history code only. This is a normal condition for DTC 024 and it should be diagnosed as a current DTC.

TEST DESCRIPTION

Steps 1-7:

The numbers below refer to the step numbers on the diagnostic table.
2. This step inspects the PPS module connector.
3. This step inspects the main seat harness connector.
4. This step tests the PPS ground circuit for an open or high resistance.
5. This step tests the PPS ignition 1 voltage circuit for a short to ground, an open, or high resistance.