Caution: If the vehicle interior is exposed to moisture and becomes soaked up to the level of the sensing and diagnostic module (SDM), the SDM and SDM harness connector must be replaced. The SDM could be activated when powered, which could cause airbag deployment and result in personal injury.
The Diagnostic System Check - SIR must always be the starting point for any SIR diagnosis. The Diagnostic System Check reveals DTCs through the use of the scan tool. The diagnostic procedures used in this section are designed to find any repair SIR conditions. To get the best results, it is important to use the diagnostic charts and follow the sequence listed below.
- Perform the Diagnostic System Check - SIR, which reveals DTCs through the use of scan tool. It also checks for proper air bag indicator operation.
- Refer to the proper diagnostic chart as directed by the Diagnostic System Check - SIR. Bypassing these procedures may result in extended diagnostic time, incorrect diagnosis, and incorrect parts replacement.
- Repeat the Diagnostic System Check - SIR after any repair or diagnostic procedures have been performed to ensure that the repair has been made correctly and that no other malfunction exists.
Circuit Description
When the ignition switch is first turned to ON, ignition voltage is supplied from the air bag fuse to find the sensing and diagnostic module (SDM) at the input terminal A1. The SDM responds by flashing the air bag indicator 7 times and then turning it OFF while the SDM performs tests on the SIR.
Diagnostic Aids
The order in which DTCs are diagnosed is very important. Failure to diagnose the DTCs in the order specified may result in extended diagnostic time, incorrect diagnosis, and incorrect parts replacement.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
|
Caution: Refer to Sensing and Diagnostic Module Voltage after Ignition is Turned Off Caution in the Preface section. Caution: Refer to Sensing and Diagnostic Module Handling Caution in the Preface section. | ||||
1 |
Does the warning lamp turn OFF after 4 seconds? | -- | System OK | Go to Step 2 |
2 |
Are there any active fault codes? | -- | Go to Step 3 | |
3 | Check fuse F8. Is the fuse F8 open? | -- | Go to Step 4 | Go to Step 5 |
4 | Replace fuse F8. Is the replacement complete? | -- | System OK | -- |
5 |
Is the wiring harness shorted to ground? | -- | Go to Step 6 | Go to Step 7 |
6 | Repair a short to ground between fuse F8 and terminal 3 of connector C214. Is the repair complete? | -- | System OK | -- |
7 |
Is the wiring harness shorted to ground? | -- | Go to Step 15 | Go to Step 8 |
8 | Use an ohmmeter to check for continuity between the DLC terminal and ground. Does the ohmmeter show the specified value? | 0 ohms | Go to Step 9 | Go to Step 10 |
9 | Repair the open DLC ground circuit. Is the repair complete? | -- | System OK | -- |
10 |
Does the voltmeter show the specified value? | 11-14 V | Go to Step 12 | Go to Step 11 |
11 | Repair the power supply for the cigar lighter socket. Is the repair complete? | -- | System OK | -- |
12 | Check for a short to ground or an open circuit between the DLC terminal and terminal 4 of connector C214. Is the wiring harness shorted to ground or open? | -- | Go to Step 13 | Go to Step 14 |
13 | Repair a short to ground or open circuit between terminal J13 of the DLC and terminal 4 of connector C214. Is the repair complete? | -- | System OK | -- |
14 | Check for a short to ground or an open between terminal 4 of connector C214 and terminal 9 of the SDM connector. Is the wiring harness shorted to ground or open? | -- | Go to Step 15 | Go to Step 16 |
15 | Replace the SDM wiring harness. Is the repair complete? | -- | System OK | -- |
16 | Replace the SDM. Is the repair complete? | -- | System OK | -- |
