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

### Circuit Description

When you first turn the ignition switch to the ON position, the inflatable restraint Sensing and Diagnostic Module (SDM) performs tests to diagnose critical malfunctions within itself. Upon passing these IGNITION 1, 23 VLR and deployment loop voltages are measured to make sure they are within their respective normal voltage ranges. The SDM monitors the voltages at DRIVER SIDE LOW terminal 10 and PASSENGER SIDE LOW terminal 3 in order to detect shorts to ground in the inflator module circuits.

### Conditions for Setting the DTC

• | The driver deployment loop is not open.

• | The passenger deployment loop is not open.

• | The passenger deployment loop is not shorted to voltage.

• | The voltage at PASSENGER SIDE LOW terminal 3 is more than 1.5 volts.

• | The voltage at DRIVER SIDE LOW terminal 10 is less than 1.5 volts for 500 milliseconds.

The following tests check for the DTC. These tests occur when IGNITION 1 is within the normal operating voltage range:

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

• | The CONTINUOUS MONITORING test.

### 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

• | Clear the Current DTC when the voltage at DRIVER SIDE LOW terminal 10 is more than 1.5 volts for 500 milliseconds.

• | Clear the History DTC under the following conditions:

- | You issue a scan tool CLEAR CODES command.

- | Once 250 malfunction free ignition cycles have occurred.

### Diagnostic Aids

A shot-to-ground in the inflatable restraint steering module circuit can cause an intermittent condition. Moving wires while monitoring DRIVER SENSELO may help locate the fault. Inspect the GRN/RED wire and the GRN wire carefully for cut or chafed wires. The diagnostic table directs the technician to note the entry value of DRIVER 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 in this section.

### Test Description

Numbers below refer to step numbers on the diagnostic table.

1. This step determines the DRIVER SIDE LOW voltage measured by the inflatable restraint Sensing and Diagnostic Module (SDM).

2. This step isolates the malfunction to one side of the yellow 2-way connector on the inflatable restraint steering wheel module coil. This connector is located near the base of the steering column.

3. This step determines whether the malfunction is in the inflatable restraint steering wheel module coil or in the inflatable restraint steering wheel module.

4. This step determines whether the malfunction is in the GREN/RED wire.

5. This step determines whether the malfunction is in the GRN wire.

#### DTC B1024 Driver Deployment Loop Short to Ground

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 LOCK position.
2. Connect a scan tool to the data link connector. Follow the directions in the instruction manual of the scan tool.
3. Turn the ignition switch to the ON position
4. Request the SIR data list display.
5. Read the DRIVER SIDE LOW voltage DRIVER SENSELO. Record this value on the repair order

Is the DRIVER SENSELO less than the specified value?

3.3 V

Go to Step 3

Refer to Diagnostic Aids

3 |

1. Turn the ignition switch to the LOCK position.
2. Disconnect the yellow connectors from the inflatable restraint steering wheel module and the inflatable restraint IP module. These connectors are located near the base of the steering column and behind the IP compartment.
3. Connect the J 38715-A SIR Driver/Passenger Load Tool to the inflatable restraint steering wheel module harness connector and to the inflatable restraint IP module harness connector.
4. Turn the ignition switch to the ON position.
5. Using the scan tool, request the SIR data list display and read the DRIVER SIDE LOW voltage DRIVER SENSELO.

Is DRIVER SENSELO less than the specified value?

3.3 V

Go to Step 7

Go to Step 4

4 |

1. Turn the ignition switch to the LOCK position.
2. Remove the inflatable restraint steering wheel module from the steer wheel. Refer to Supplemental Inflatable Restraint (SIR) Steering Wheel and Column.
3. Disconnect the J 38715-A from the 2-way connector at the base of the steering column.
4. Reconnect the 2-way connector at the base of the steering column.
5. Connect the J 38715-A to the inflator module connector on the steering column.
6. Turn the ignition switch to the ON position.
7. Using the scan tool, request the SIR data list display, and read the DRIVER SIDE LOW voltage DRIVER SENSELO.

Is DRIVER SENSELO less than the specified value?

3.3 V

Go to Step 6

Go to Step 5

5 |

1. Turn the ignition switch to the LOCK position.
2. Replace the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .

Have you replaced the inflatable restraint steering wheel module?

--

Go to Step 11

--

6 |

1. Turn the ignition switch to the LOCK position.
2. Remove the inflatable restraint steering wheel module coil and inspect the connecting wires for damage.
3. Determine and repair the cause of damage. Replace the inflatable restraint steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Have you replaced the inflatable restraint steering wheel module coil?

--

Go to Step 11

--

7 |

1. Turn the ignition switch to the LOCK 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 terminal 9 to terminal 6 (ground).

Is the resistance reading less than the specified value?

OL

Go to Step 8

Go to Step 9

8 | Repair a short to ground condition in the GRN/RED wire. Is the circuit repair complete? | -- | Go to Step 11 | --
9 | Measure the resistance on the SDM harness connector from terminal 10 to terminal 6 (ground). Is the resistance reading less than the specified value? | OL | Go to Step 10 | Go to Integrity Check
10 | Repair a short to ground condition in the GRN wire. Is the circuit repair complete? | -- | Go to Step 11 | --
11 | Reconnect and mount all the SIR system components. Have you reconnected and properly mounted all of the SIR components? | -- | Go to Step 12 | --
12 | Clear the SIR diagnostic trouble codes. Have you cleared the SIR diagnostic trouble codes? | -- | Go to SIR Diagnostic System Check | --