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

### Circuit Description

When the ignition switch is turned to the ON position, the CLAMP 15 CRUISE Fuse applies battery voltage to the AIR BAG warning lamp that is connected to the INFLATABLE RESTRAINT INDICATOR, terminal 6, of the inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM). The ignition switch applies battery voltage to the IGNITION input, terminal 5, of the SDM. The SDM responds by flashing the AIR BAG Warning Lamp seven times and then turning it OFF. The SDM monitors the lamp output driver by comparing the output state at the INFLATABLE RESTRAINT INDICATOR, terminal 6, to the microprocessor commanded state.

### Conditions for Setting the DTC

DTC 43 will set when:

• | The specified value for the output state at the INFLATABLE RESTRAINT INDICATOR, terminal 6, does not match the commanded state for 1.25 seconds.

• | The voltage measured at terminal 6 is above a specified value.

This test runs during the Initialization and Continuous Monitoring when the ignition voltage is above a specified value.

### Action Taken When the DTC Sets

• | The SDM sets a DTC 43.

• | The SDM attempts to turn ON the AIR BAG warning lamp.

### Conditions for Clearing the DTC

Current and History DTC codes must be cleared using a scan tool Clear DTC Information command. If the circuit fault has been successfully repaired and the conditions which caused the DTC to set are no longer existing, the DTC may be cleared using the scan tool. If the output state at the INFLATABLE RESTRAINT INDICATOR, terminal 6, matches the microprocessor commanded state, the current DTC 43 will change to a history DTC 43, which may be cleared using the scan tool.

### Diagnostic Aids

These malfunctions are addressed in the SIR Diagnostic System Check. Perform the SIR Diagnostic System Check before continuing with this table.

### Test Description

1. This step checks terminal 13 and terminal 19 of the instrument cluster wiring harness connector for corrosion or damaged terminals.

2. This step checks terminal 13 and terminal 19 of the instrument cluster for corrosion or damaged terminals.

3. This step checks to see if the AIR BAG warning lamp is OK.

4. This step checks the AIR BAG warning lamp socket within the instrument cluster for corrosion or damaged terminals.

5. This step checks for a short between terminal 13 and terminal 19 of the instrument cluster wiring harness connector.

6. This step checks for a short between terminal 13 and terminal 19 of the instrument cluster.

7. This step checks the SDM wiring harness connector for corrosion or damaged terminals.

8. This step determines if there is a short to B+ in CKT XB20 or if there is a malfunctioning SDM.

#### DTC 43 AIR BAG Warning Lamp Circuit Short to Voltage

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. Disconnect the instrument cluster wiring harness connector. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
3. Inspect terminal 13 and terminal 19 of the instrument cluster wiring harness connector for corrosion or damaged terminals.

Is terminal 13 or terminal 19 of the instrument cluster wiring harness connector corroded or damaged?

--

Go to Step 3

Go to Step 4

3 | Repair terminal 13 or terminal 19 of the instrument cluster wiring harness connector. Refer to Connector Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 4 | --
4 | Inspect terminal 13 and terminal 19 of the instrument cluster for corrosion or damaged terminals. Is terminal 13 or terminal 19 of the instrument cluster corroded or damaged? | -- | Go to Step 5 | Go to Step 6
5 | Replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console. Is the repair complete? | -- | Go to Step 18 | --
6 |

1. Remove the AIR BAG warning lamp.
2. Inspect the AIR BAG warning lamp.

Is the AIR BAG warning lamp OK?

--

Go to Step 8

Go to Step 7

7 | Replace the AIR BAG warning lamp. Is the repair complete? | -- | Go to Step 18 | --
8 | Inspect the AIR BAG warning lamp socket within the instrument cluster for corrosion or damaged terminals. Is the AIR BAG warning lamp socket corroded or damaged? | -- | Go to Step 5 | Go to Step 9
9 | Use the J 39200 Digital Multimeter (DMM) to measure the resistance between terminal 13 and terminal 19 of the instrument cluster wiring harness connector. Is the measured resistance less than the specified value? | OL | Go to Step 10 | Go to Step 11
10 |

1. Locate a short between CKT X13 and CKT XB20.
2. Repair the short between CKT X13 and CKT XB20.

Is the repair complete?

--

Go to Step 18

--

11 | Use the J 39200 Digital Multimeter (DMM) to measure the resistance between terminal 13 and terminal 19 of the instrument cluster. Is the measured resistance less than the specified value? | OL | Go to Step 5 | Go to Step 12
12 |

1. Disconnect the inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic and Seat Belt Pretensioner Module Replacement .
2. Inspect terminal 6 of the SDM wiring harness connector for damaged terminals or corrosion.

Is terminal 6 of the SDM wiring harness connector corroded or damaged?

--

Go to Step 13

Go to Step 14

13 | Use the J 42250 Catera Terminal Repair Kit to repair the SDM wiring harness connector. Is the repair complete? | -- | Go to Step 14 | --
14 | Inspect terminal 6 of the SDM for damaged terminals or corrosion. Is terminal 6 of the SDM corroded or damaged? | -- | Go to Step 15 | Go to Step 16
15 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic and Seat Belt Pretensioner Module Replacement . Is the repair complete? | -- | Go to Step 18 | --
16 |

1. Turn the ignition switch to the ON position.
2. Use the J 39200 to measure the voltage between terminal 6 of the SDM wiring harness connector and a known good ground.

Is the measured voltage more than the specified value?

1 V

Go to Step 17

Go to Sensing and Diagnostic Module Integrity Check

17 |

1. Locate a short to B+ in CKT XB20.
2. Repair the short to B+ in CKT XB20.

Is the repair complete?

--

Go to Step 18

--

18 | Reconnect all the SIR components, making sure all the components are properly mounted? Have all SIR components been reconnected and properly mounted? | -- | Go to Step 19 | --
19 | Use the scan tool to clear all current and history SIR DTCs. Have all current and history SIR DTCs been cleared? | -- | Go to SIR Diagnostic System Check | --