GM Service Manual Online
For 1990-2009 cars only

Circuit Description

DTC 71 is an indication of a potential internal SDM malfunction and will set if any of the following conditions is detected:

    • Reserve voltage discharge time has failed for three consecutive ignition cycles.
    • The calculated checksum for internal memory does not match the stored value.
    • The temporary memory storage area is malfunctioning.
    • The permanent memory storage area is malfunctioning.
    • The voltage measured at driver low and passenger low are too high.
    • The voltage measured at driver low and passenger low are too low.
    • The accelerometer inside the SDM is malfunctioning.
    • The driver current source and/or passenger current source is malfunctioning.
    • The SDM is unable to read from or write to electronically erasable programmable read only memory (EEPROM).
    • The arming sensor inside the SDM is not closed during a deployment event.

Conditions for Setting the DTC

DTC 71 will set when any of the indicated malfunctions is detected by the SDM. The malfunctions are detected at various times:

    • Turn-on.
    • Continuous monitoring.
    • Resistance measurement test.

Action Taken When the DTC Sets

The SDM turns on the AIRBAG indicator and sets a DTC 71.

Conditions for Clearing the DTC

DTC 71 Will Clear When A scan tool CLEAR CODES command is received by the SDM. Some of the malfunctions will allow the AIRBAG indicator to turn off only briefly and then turn on again.

Caution: Refer to Sensing and Diagnostic Module Voltage after Ignition is Turned Off Caution in the Preface section.

Caution: Refer to Sensing and Diagnostic Module Handling Caution in the Preface section.

Step

Action

Yes

No

1

Perform the Diagnostic System Check - SIR.

Is the Diagnostic System Check - SIR complete?

Go to Step 2

Go to Diagnostic System Check - SIR

2

Check for current or history DTCs.

Is either DTC 18 or DTC 24 also set as a current or a history DTC?

Go to the diagnostic table for DTC 018 or DTC 024

Go to Step 3

3

  1. Turn OFF the ignition and remove the key.
  2. Disconnect the passenger airbag and the yellow clock spring connector on the steering column.
  3. Replace the SDM. The arrow must be pointing toward the front of the vehicle.
  4. Connect all SIR components, and ensure that all components are properly mounted.

Did you complete the repair?

Go to Diagnostic System Check - SIR

--