GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2008 🢒 Vibe - FWD 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC B1793

Circuit Description

The passenger presence system (PPS) sensor power supply circuits consists of the PPS sensors and the PPS module. The PPS module monitors the PPS sensor power supply circuits. If the sensing and diagnostic module (SDM) detects a malfunction within the sensor power supply circuits, a DTC will be set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1793 Passenger Presence System Power Supply Circuit

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The SDM detects a PPS sensor power supply circuit malfunction.

Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

    • An open or high resistance in a PPS sensor power supply circuit
    • A short to ground or voltage in a PPS sensor power supply circuit
    • A short between the PPS sensor power supply circuits
    • A malfunctioning PPS sensor
    • An internal PPS module malfunction

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests the PPS sensor power supply circuits for an open or high resistance, a short to ground and a short to voltage.

    2.

  2. This step tests to see if the malfunction is caused by the PPS sensor.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Is DTC B1793 set as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3
  1. Turn OFF the ignition.
  2. Disconnect the passenger presence system (PPS) sensor connectors.
  3. Inspect both the component and harness sides of the connector for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections .

Does the connector exhibit any signs of damage or corrosion?

Go to Step 4

Go to Step 5

4
  1. If the component side of a PPS sensor connector is damaged, the PPS sensor must be replaced. Refer to Front Seat Adjuster Replacement .
  2. If the harness side of a PPS sensor connector is damaged, replace the harness side of the connector. Refer to Connector Repairs .

Did you complete the replacement?

Go to Step 10

--

5
  1. Turn OFF the ignition.
  2. Disconnect the PPS module connector.
  3. Inspect the PPS module connector for the following conditions:
    4. • Corrosion
    • Damaged terminals
    • Poor contact/terminal tension

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

Test the PPS sensor power supply circuits for the following conditions

    • An open or high resistance
    • A short to ground
    • A short to voltage
    • A short between circuits
        For all of the above conditions, refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 7

7

Replace the PPS module. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

Go to Step 8

--

8

  1. Reconnect all SIR components.
  2. Verify that all components, connectors, and connector position assurances (CPAs) are properly mounted.
  3. Use the scan tool in order to Clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 9

System OK

9

Replace the PPS sensors. Refer to Front Seat Adjuster Replacement .

Did you complete the replacement?

Go to Step 10

--

10
  1. Reconnect all SIR components.
  2. Verify that all components, connectors, and CPAs are properly mounted.
  3. Use the scan tool in order to Clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK