GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2002 🢒 Eldorado 🢒 Restraints 🢒 SIR 🢒 DTC B1151

Circuit Description

The inflatable restraint sensing and diagnostic module (SDM) contains a sensing device that converts vehicle velocity changes to an electrical signal. The SDM processes the generated electrical signal and compares it to a value stored in memory. When the generated signal exceeds the stored value, 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 frontal inflator modules. This deploys the air bags and causes DTC B1151and B1152 to set.

Conditions for Running the DTC

Ignition voltage must be present.

Conditions for Setting the DTC

Ignition voltage must be present and the SDM must have commanded an air bag deployment.

Action Taken When the DTC Sets
    • The SDM sets a DTC B1151 and DTC B1152.
    • The SDM commands the AIR BAG warning lamp ON via Class 2 serial data.
    • The SDM records the crash data.

Conditions for Clearing the DTC

A scan tool CLEAR DTCs command is received by the SDM.

Test Description

The following numbers refer to the step numbers in the diagnostic table:

  1. If the inflator modules has not deployed, DTC B1151and B1152 may have set falsely.

    2.

  2. If DTC B1151 and B1152 has set with no signs of impact/collision, the DTC has set falsely.

Step

Action

Yes

No

1

Did you perform A Diagnostic System Check - SIR?

Go to Step 2

Go to Diagnostic System Check - SIR

2

Did DTC B1153 set?

Go to DTC B1153

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Inspect the vehicle for any signs of air bag deployment.

Does the vehicle show any signs of air bags deployment?

Go to Step 6

Go to Step 4

4

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

Does the vehicle show any signs of impact/collision?

Go to Step 6

Go to Step 5

5

Replace the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

Go to Step 7

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6

Replace all the components and perform inspections as required following an accident. Refer to Inflator Module Handling and Scrapping .

Did you complete the appropriate inspections and necessary repairs?

Go to Step 7

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7
  1. Reconnect all SIR components.
  2. Verify that all components, connectors, and CPAs are properly mounted.

Did you complete the repair?

Go to Diagnostic System Check - SIR

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