GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2003 🢒 Envoy - 2WD 🢒 Restraints 🢒 SIR 🢒 DTC B0053

Circuit Description

The inflatable restraint sensing and diagnostic module (SDM) contains sensing devices that convert vehicle velocity changes to electrical signals. The SDM processes the generated electrical signals and compares them to values stored in memory. When the generated signals exceed the stored values, the SDM performs additional signal processing and compares the generated signals to signals stored in memory. When two of the generated signals exceed the stored values, the SDM will cause current to flow through the inflator modules, deploying the inflator modules. DTC B0053 will set along with DTC B0051 when a deployment occurs while a circuit malfunction is present in any one of the deployment loops.

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The DTC will set when the SDM detects a frontal crash, up to 30 degrees off the centerline of the vehicle, of sufficient force to warrant deployment of the inflator modules.

Action Taken When the DTC Sets
    • The SDM turns the AIR BAG indicator ON.
    • The SDM records crash data.

Conditions for Clearing the DTC

DTC B0053 is a latched code. You cannot clear a latched code. Replace the SDM after following the instructions in the diagnostic table.

Diagnostic Aids

DTC B0053 will be accompanied by another DTC (other than DTC B1000 and DTC B0051). Repair the malfunction causing the other DTCs before installing a new SDM.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views

1

Did you perform A Diagnostic System Check - SIR?

Go to Step 2

Go to Diagnostic System Check - SIR

2

  1. Turn OFF the ignition.
  2. Inspect the vehicle for signs of inflator module(s) deployment.

Does the vehicle show any signs of inflator module(s) deployment?

Go to Step 5

Go to Step 3

3

Inspect the front of the vehicle and undercarriage for signs of impact/collision.

Does the vehicle show any signs of impact/collision?

Go to Step 5

Go to Step 4

4

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

Did you complete the replacement?

Go to Step 6

--

5
  1. Install a scan tool.
  2. With a scan tool, observe the SIR DTC display.
  3. If a history DTC exists, refer to Diagnostic Aids for that specific DTC and diagnose the problem.
  4. Replace components and perform inspections as required following an accident. Refer to Repairs and Inspections Required After a Collision.

Did you complete the action?

Go to Step 6

--

6
  1. Reconnect all SIR 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 2

System OK