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. The SDM monitors the voltage levels at the PSIR enable and PSIR disable terminals of the SDM to determine the position of the inflatable restraint IP module switch. The SDM then performs the following continuous diagnostic tests on the deployment loops:
| • | Deployment loop voltage out of range test |
| • | Deployment loop resistance measurement test |
If the voltage out of range test detects a short to voltage condition, the resistance measurement test for that deployment loop will not be performed.
Conditions for Running the DTC
| • | Ignition 1 voltage is within the normal operating voltage range. |
| • | PSIR enable circuit is not shorted to voltage. |
| • | PSIR disable circuit is not shorted to voltage. |
Conditions for Setting the DTC
| • | The voltage detected at PSIR enable terminal and PSIR disable terminal are less than 1.0 volts when the PASSENGER AIR BAG OFF LED is commanded OFF. |
| • | The voltage detected at PSIR enable terminal and PSIR disable terminal are greater than 1.0 volt when the PASSENGER AIR BAG OFF LED is commanded ON. |
Action Taken When the DTC Sets
| • | The inflatable restraint IP module switch is defaulted to a calibrated state. |
| • | The SDM commands ON the PASSENGER AIR BAG OFF LED via Class 2 serial data. |
Conditions for Clearing the DTC
| • | You issue a scan tool CLEAR CODES command. |
| • | A history DTC will clear once 255 malfunction free ignition cycles have occurred. |
When the SDM detects that no DTCs are present, the SDM commands the AIR BAG warning lamp OFF.
Diagnostic Aids
The following can cause an intermittent condition:
| • | A short between the PSIR enable and PSIR disable circuits. |
| • | Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Test Description
The numbers below refer to the step numbers on the diagnostic table:
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Test determines if the AIR BAG ON lamp illuminates when the inflatable restraint IP module switch is in the ON position.
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Tests for a poor connection at the inflatable restraint IP module switch harness connector.
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Tests for a poor connection at the inflatable restraint IP module LED harness connector.
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Tests for a poor connection at the inflatable restraint IP module LED connector.
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Tests for an open or high resistance in the inflatable restraint IP module LED.
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Test determines whether the malfunction is in the inflatable restraint IP module switch ground circuit.
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Test determines whether the malfunction is in the power feed circuit between the fuse block and the inflatable restraint IP module switch.
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Tests for proper contact or corrosion of the inflatable restraint sensing and diagnostic module (SDM) harness connector.
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Tests for an open or high resistance in the passenger SIR enable circuit.
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Tests for a short to ground in the passenger SIR enable circuit.
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Tests for a short to voltage in the passenger SIR enable circuit.
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Tests for a short between the passenger SIR enable and disable circuits.
Step | Action | Value(s) | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the SIR Diagnostic System Check? | -- | Go to Step 2 | |||||||||
Does the PASSENGER AIR BAG OFF LED illuminate? | -- | Go to Step 16 | Go to Step 3 | |||||||||
Does the connector exhibit any signs of corrosion, terminal damage, or poor connections? | -- | Go to Step 4 | Go to Step 5 | |||||||||
4 | Repair or replace the the inflatable restraint IP module switch harness connector. Refer to Connector Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
5 | Inspect the inflatable restraint IP module switch terminals for the following conditions:
Do the terminals exhibit any signs of corrosion, terminal damage, or poor connections? | -- | Go to Step 27 | Go to Step 6 | ||||||||
Does the connector exhibit any signs of corrosion, terminal damage, or poor connections? | -- | Go to Step 7 | Go to Step 8 | |||||||||
7 | Repair or replace the inflatable restraint IP module LED harness connector. Refer to Connector Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
Does the connector exhibit any signs of corrosion, terminal damage, or poor connections? | -- | Go to Step 9 | Go to Step 10 | |||||||||
9 | Repair or replace the inflator restraint IP module LED connector. Refer to Connector Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
Use the J 39200 DMM to measure the resistance of the inflatable restraint IP module LED. Does the resistance measure less than the specified value? | 0.8 ohms | Go to Step 11 | Go to Step 12 | |||||||||
11 | Replace the inflatable restraint IP module LED. Refer to Inflatable Restraint Instrument Panel Module Disable Switch LED Replacement . Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
Does the resistance measure greater than the specified value? | 5 ohms | Go to Step 13 | Go to Step 14 | |||||||||
13 | Locate and repair an open or high resistance in the inflatable restraint IP module switch ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
Does the voltage measure greater than the specified value? | 1 V | Go to Step 15 | Go to Step 16 | |||||||||
15 | Locate and repair an open or high resistance in the inflatable restraint IP module switch power feed circuit between the fuse block and the IP module switch. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
16 |
Does the active switch show the specified state? | Enabled | Go to Step 28 | Go to Step 17 | ||||||||
Does the connector exhibit any signs of corrosion, terminal damage, or poor connections? | -- | Go to Step 18 | Go to Step 19 | |||||||||
18 | Repair or replace the inflatable restraint sensing and diagnostic module (SDM) wiring harness connector. Refer to Connector Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
Does the resistance measure greater than the specified value? | 5 ohms | Go to Step 20 | Go to Step 21 | |||||||||
20 | Locate and repair an open or high resistance in the PSIR enable circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
Does the resistance measure less than the specified value? | 0 L | Go to Step 22 | Go to Step 23 | |||||||||
22 | Locate and repair a short to ground in the PSIR enable circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
Does the voltage measure greater than the specified value? | 2 V | Go to Step 24 | Go to Step 25 | |||||||||
24 | Locate and repair a short to voltage in the PSIR enable circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
Does the resistance measure less than the specified value? | O.8 ohms | Go to Step 26 | Go to Step 27 | |||||||||
26 | Locate and repair a short between the PSIR enable and PSIR disable circuits. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
27 | Replace the inflatable restraint IP module switch. Refer to Inflatable Restraint Instrument Panel Module Disable Switch Replacement . Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
28 | Replace the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement Did you complete the repair? | -- | Go to Step 29 | -- | ||||||||
29 |
Did you complete the action? | -- | -- |
