GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Catera 🢒 Restraints 🢒 SIR 🢒 DTC 066

Circuit Description

The inflatable restraint sensing and diagnostic module (SDM) contains a sensing device which converts vehicle velocity changes to an electrical signal. The SDM processes the generated electrical signals and compares them to values stored in memory. When the generated signals exceed 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 causes current to flow through the inflatable restraint steering wheel module, deploying the steering wheel module and causing DTC 66 to set.

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 of sufficient force to warrant deployment of the steering wheel module.

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

Step

Action

Yes

No

Schematic Reference: SIR Schematics

1

Did you perform the Diagnostic System Check - SIR?

Go to Step 2

Go to Diagnostic System Check - SIR

2
  1. Turn OFF the ignition.
  2. Remove the ignition key.
  3. Inspect the vehicle for signs of steering wheel module deployment.

Does the vehicle exhibit signs of steering wheel module 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 the 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