GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2007 🢒 Express - AWD 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC 1049-1050

Circuit Description

The inflatable restraint passenger presence system (PPS) is used to monitor the pressure profile of any occupant that is sitting in the front outboard passenger seat and communicate the profile classification to the sensing and diagnostic module (SDM). The SDM will either enable or suppress the deployment of the instrument panel (I/P) module based on the profile classification of the occupant. If the PPS detects that the vehicle voltage is too low or high the PPS will then set a DTC within the PPS, then the PPS will communicate to the SDM through a non class 2 communications circuit that a PPS fault is present. The SDM will then set DTC B0092 indicating a problem within the PPS.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC 1049 PPS System Fault
    • DTC 1050 PPS System Fault

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The PPS has detected supply battery voltage too low or too high.

Action Taken When the DTC Sets
    • The PPS will set a DTC then communicate with the SDM via non class 2 circuit.
    • The SDM will set DTC B0092.
    • The SDM disables the I/P module deployment loop.
    • The SDM commands the AIR BAG indicator ON via class 2 serial data.

Diagnostic Aids

DTC 1049 is an indication that the supply battery voltage (ignition 1) to the PPS too low and could be from corrosion and DTC 1050 is an indication that the supply battery voltage (ignition 1) to the PPS too high. The following are possible causes of the malfunction:

    • A malfunctioning charging system
    • High resistance in the PPS ignition 1 circuit
    • The PPS connector
    • A malfunctioning PPS

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. 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. Inspect to see if DTC 1050 is set indicating that the supply battery voltage is too high.

    2.

  2. Inspect to see if DTC 1049 is set indicating that the supply battery voltage is too low.

    3.

  3. This step tests the PPS ignition 1 for high resistance or short to ground.

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

  1. Connect the scan tool.
  2. Go to the passenger presence system (PPS) menu, then retrieve the DTCs. Refer to Passenger Presence System Displaying Code Procedure .

Does DTC 1050 set as current?

Go to Diagnostic System Check - Vehicle

Go to Step 3

3

Does DTC 1049 set as current?

Go to Step 4

Go to Step 8

4
  1. Turn OFF the ignition.
  2. Disconnect the PPS module connector located under the front passenger seat. Refer to Inflatable Restraint Passenger Presence System Replacement - Front .
  3. Inspect the component and harness side of the connector for the PPS for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Does connector exhibits any signs of damage or corrosion?

Go to Step 5

Go to Step 6

5
  1. If the PPS connector is damaged, the PPS must be replaced. Refer to Inflatable Restraint Passenger Presence System Replacement - Front .
  2. If the wiring harness side of the PPS connector is damaged, replace the harness side of the connector. Refer to Connector Repairs .

Did you find and correct the condition?

Go to Step 10

--

6

Test the PPS ignition 1 circuit for high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 7

7

Test the PPS ground circuit for high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 8

8
  1. Reconnect all components.
  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 9

System OK

9
  1. Turn OFF the ignition.

    2. Important: The PPS is a calibrated system. The PPS must be check for preloads after replacement.

  2. Replace the PPS. The PPS is only serviceable as PPS and seat bottom foam assembly. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

10
  1. Verify that all components, connectors and connector position assurances (CPA)s are properly mounted.
  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 2

System OK