GM Service Manual Online
For 1990-2009 cars only

Circuit Description

DTC B1000 is an indication of a potential internal inflatable restraint sensing and diagnostic module (SDM) malfunction. DTC B1000 will set upon detection of any condition in the table below.

Conditions for Setting the DTC

Malfunction

Detection Test

23 VLR is out of the normal operating voltage range.

Power-On, continuous monitoring

Crash data recording reserve voltage discharge time failure for three consecutive ignition cycles.

Power-On

The calculated checksum for internal memory does not match the stored value.

Power-On

The driver or passenger deployment loop is shorted to ground.

Continuous monitoring

The accelerometer is malfunctioning.

Power-On, continuous monitoring

The driver or passenger current source is malfunctioning.

Resistance measurement

The temporary memory storage area is malfunctioning.

Power-On

The inflatable restraint sensing and diagnostic module (SDM) is unable to read from or write to EEPROM.

Power-On

The arming sensor inside the inflatable restraint sensing and diagnostic module (SDM) is not closed during a deployment event.

Asynchronously

The device inside the inflatable restraint sensing and diagnostic module (SDM) that arms the system for deployment is malfunctioning.

Power-On, continuous monitoring

The permanent memory storage area is malfunctioning.

Power-On

Action Taken When the DTC Sets

The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.

Conditions for Clearing the DTC

    • You issue a scan tool CLEAR CODES command.
    • A history DTC will clear once 255 malfunction free ignition cycles have occurred.
    • The fault condition detected by the SDM goes away.

When the SDM detects that no DTCs are present, the SDM commands the AIR BAG warning lamp OFF.

Diagnostic Aids

When you issue a scan tool CLEAR CODES command, some of the indicated malfunctions will only allow the AIR BAG warning lamp to turn OFF briefly then come back ON.

Step

Action

Value(s)

Yes

No

1

Did you perform the SIR Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - SIR

2

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 Diagnostic System Check - SIR

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