Circuit Description
The ECU-B Fuse supplies battery voltage at all times to the AIR BAG warning lamp that is connected to the AIR BAG Indicator Control connector C2 terminal 2. When the ignition switch is turned to ACC or ON, battery voltage is applied to the inflatable restraint Sensing and Diagnostic Module (SDM) at connector C2 terminal 4. The SDM responds by illuminating the AIR BAG warning lamp for approximately six seconds while performing diagnostic tests on the SIR system. The IGN Fuse supplies battery voltage to the SDM at connector C2 terminal 3 when the ignition switch is in the ON or START positions.
Test Description
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This test checks for a short to ground in the air bag indicator control circuit or the instrument cluster.
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This test checks for a short to ground in the air bag indicator control circuit to the instrument cluster.
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This test checks for a short to ground in the air bag indicator control circuit to the data link connector (underhood).
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This test checks for a short to ground in the air bag indicator control circuit between the SDM and SP255.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
2 | Turn the ignition switch to the LOCK position. Is the AIR BAG warning lamp ON? | -- | ||
Is the resistance measured within the specified values? | 0-5 ohms | |||
Is the resistance measured less than the specified value? | OL (Infinite) | |||
5 | Repair a short to ground condition in the BLK/YEL wire between SP255 and the instrument cluster. Refer to Wiring Repair in this section. Are all the repairs complete? | -- | -- | |
6 | Service the instrument cluster. Refer to Instrument Cluster System Check in Instrument Panel, Gauges and Console. Are all the repairs complete? | -- | -- | |
Measure the resistance between the Data Link Connector (Underhood) terminal 5 (AB) and ground. Is the resistance measured within the specified values? | 0-5 ohms | |||
8 | Repair a short to ground condition in the BLK/YEL wire between SP255 and the DLC. Refer to Wiring Repair . Are all the repairs complete? | -- | -- | |
Is the resistance measured less than the specified values? | OL (Infinite) | |||
10 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Are all the repairs complete? | -- | -- | |
11 | Replace SP255. Refer to Wiring Repair . Are all the repairs complete? | -- | -- | |
12 | Remove the ECU-B Fuse. Is the ECU-B Fuse good? | -- | ||
13 | Measure the voltage from each terminal of the ECU-B fuseholder. Is either voltage reading greater than the specified value? | 1 V | ||
14 |
Is the voltage reading within the specified value? | 9-14 V | ||
15 |
Is the AIR BAG warning lamp bulb good? | -- | ||
16 | Repair a short to ground in the RED/GRN wire. Refer to Wiring Repair . Are all the repairs complete? | -- | -- | |
17 | Repair an open in the power feed to the ECU-B Fuse. Refer to Wiring Repair . Are all the repairs complete? | -- | -- | |
18 | Repair an open in the RED/GRN wire. Refer to Wiring Repair in this section. Are all the repairs complete? | -- | -- | |
19 | Replace the AIR BAG warning lamp bulb. Refer to Instrument Cluster Bulb Replacement in Instrument Panel, Gauges and Console. Are all the repairs complete? | -- | -- | |
20 | Reconnect all the SIR components. Make sure all the components are properly mounted. Have all the SIR components been properly mounted? | -- | -- |
