For 1990-2009 cars
SIR Components
SIR Schematics
Handling ESD Sensitive Parts Notice
SIR Caution
SIR Caution
Handling ESD Sensitive Parts Notice

### Circuit Description

When you first turn the ignition switch to the RUN position, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. Upon passing these tests IGNITION, 23VLR and the deployment loop voltages are measured to make sure they are within their respective normal voltage ranges. The SDM monitors the voltages at Driver Belt Low terminal 9 and Passenger Belt Low terminal 15 to detect shorts to ground in the side inflator module circuits. The service wait time is 10 minutes. Refer to ENABLE/DISABLE procedures.

### Conditions for Setting the DTC

• | The driver and passenger seat belt pretensioner deployment loops are not open.

• | The driver seat belt pretensioner deployment loop is not shorted to voltage.

• | The voltage at Driver Belt Low terminal 9 is less than 1.25 volts for 500 milliseconds.

• | The voltage at Passenger Belt Low terminal 15 is more than 1.25 volts.

The following tests check for this DTC. These tests occur when IGNITION is within the normal operating voltage range.

• | POWER-ON-When the malfunction is detected in this test, the RESISTANCE MEASUREMENT test will not be performed.

• | CONTINUOUS MONITORING

### 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 voltage at Driver Belt Low terminal 15 is greater than 2.5 volts for 500 milliseconds.

• | History DTC

- | You issue a scan tool CLEAR CODES command.

- | Once 250 malfunction free ignition cycles have occurred.

### Diagnostic Aids

A short to ground in the inflatable restraint driver seat module circuit can cause an intermittent condition. Inspect CKT 2118 and CKT 2119 carefully for cutting or chafing. Wiring pigtail damage requires replacement of the inflatable restraint driver seat module. The diagnostic table directs the technician to note the entry value of LH PRETENS. SENSELO. Comparing the value of LH PRETENS. SENSELO can be helpful in determining if an intermittent condition exists.

When measurements are requested in this table, use J 39200 Digital Multimeter with the correct terminal adapter from J 35616 Connector Test Adapter Kit. When a check for proper connection is requested, refer to Intermittents and Poor Connections . When a wire, connector or terminal repair is requested, use J-38125 Terminal Repair Kit and refer to Wiring Repair .

### Test Description

The numbers below refer to the step numbers on the diagnostic table:

1. This test determines the driver seat buckle side belt low voltage measured by the inflatable restraint sensing and diagnostic module (SDM).

2. This test isolates the malfunction to one side of the driver seat buckle side belt yellow 2-way connector.

3. This test determines whether the malfunction is in CKT 2118.

4. This test determines whether the malfunction is in CKT 2119.

#### DTC B1043 LH Pretens Deployment Loop Short to GND

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 |

1. Turn the ignition switch to the OFF position.
2. Connect a scan tool to the DLC.
3. Turn the ignition switch to the RUN position.
4. Request the SIR data list display.
5. Read and record on the repair order the driver seat belt pretensioner low voltage LH PRETENS. SENSELO.

Is the LH PRETENS. SENSELO less than the specified value?

2.2 V

Go to Step 3

Refer to Diagnostic Aids

3 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the inflatable restraint front side impact module (LH) and driver seat buckle side belt yellow 2-way connectors located under the driver seat.
3. Connect J 38715-A SIR Driver/Passenger Load Tool STEERING WHEEL and PASSENGER INFLATOR connectors to the yellow 2-way harness connectors.
4. Turn the ignition switch to the RUN position.
5. Using the scan tool, request the SIR data list display.
6. Read the driver seat belt pretensioner low voltage LH PRETENS. SENSELO.

Is LH PRETENS. SENSELO less than the specified value?

2.2 V

Go to Step 5

Go to Step 4

4 |

1. Turn the ignition switch to the OFF position.
2. Inspect the driver seat buckle side belt harness for damage and proper routing.
3. Replace the driver seat buckle side belt. Refer to Seat Buckle Side Belt Replacement .

Are the repairs complete?

--

Go to Step 9

--

5 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the inflatable restraint Sensing and Diagnostic Module (SDM).
3. Disconnect the J 38715-A .
4. Measure the resistance on the SDM harness connector from terminals 8 to 7 (ground).

Is the resistance less than the specified value?

OL

Go to Step 6

Go to Step 7

6 | Repair a short to ground condition in CKT 2118. Are the repairs complete? | -- | Go to Step 9 | --
7 | Measure the resistance on the SDM harness connector from terminals 9 to 7 (ground). Is the resistance less than the specified value? | OL | Go to Step 8 | Go to Integrity Check
8 | Repair a short to ground condition in CKT 2119. Are the repairs complete? | -- | Go to Step 9 | --
9 | Reconnect all the SIR system components, make sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | Go to Step 10 | --
10 | Clear all the SIR DTCs. Have all the DTCs been cleared? | -- | Go to SIR Diagnostic System Check | --