GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2005 🢒 Vibe - AWD 🢒 Restraints 🢒 SIR 🢒 DTC B1785

Circuit Description

The passenger presence system (PPS) sensor - left front circuit consists of the PPS sensor - left front and the PPS module. The PPS module monitors the PPS sensor - left front. If the sensing and diagnostic module (SDM) detects the PPS module has received a collision detection signal, a DTC will be set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1785 Passenger Presence System Collision Detected - Left Front

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The SDM detects the PPS module has received a collision detection signal.

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:

    • PPS not properly calibrated
    • A malfunctioning PPS sensor - left front
    • 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 to see if the malfunction is caused by the PPS calibration.

    2.

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

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 B1785 set as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3

  1. Perform the Passenger Presence System (PPS) Rezeroing Procedure. Refer to Passenger Presence System Rezeroing .
  2. Use the scan tool in order to Clear the DTCs.
  3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 4

System OK

4

Replace the PPS sensor - left front. Refer to Front Seat Adjuster Replacement .

Did you complete the replacement?

Go to Step 5

--

5

  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 6

System OK

6

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

Did you complete the replacement?

Go to Step 7

--

7
  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