For 1990-2009 cars

Table 1: | DTC B1071 Internal SDM Failure

### Circuit Description

DTC B1071 is an indication of a potential internal inflatable restraint Sensing and Diagnostic Module (SDM) malfunction. DTC B1071 will set upon detection of any condition in the table below.

### Conditions for Setting the DTC

Malfunction | Detection Test
--- | ---
23 VLR voltage out of normal operating 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 voltage measured at DRIVER SIDE LOW and PASSENGER SIDE LOW is too low. | Power-On, Continuous monitoring
The device inside the Inflatable Restraint Sensing and Diagnostic Module 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 sets a Diagnostic Trouble Code.

• | The SDM turns ON the AIR BAG warning lamp.

### Conditions for Clearing the DTC

• | Current DTC- The malfunction has not been detected for 500 milliseconds.

• | History DTC

- | You issue a scan tool CLEAR CODES command.

- | Once 250 malfunction free ignition cycles have occurred.

### 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 go out briefly then come back ON.

#### DTC B1071 Internal SDM Failure

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the SIR Diagnostic System Check performed? | -- | Go to Step 2 | Go to SIR Diagnostic System Check
2 | Is DTC B1057 set? | -- | Go to DTC B1057 Driver Side Air Bag Deployment Commanded | Go to Step 3
3 | Is DTC B1058 set? | -- | Go to DTC B1058 Pass. Side Air Bag Deployment Commanded | Go to Step 4
4 |

1. Turn the ignition switch OFF.
2. Replace the inflatable restraint Sensing and Diagnostic Module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Are the repairs complete?

--

Go to SIR Diagnostic System Check

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