When you first turn ON the ignition, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. Then the SDM 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.
Deployment loop voltage out of range test:
• | Ignition 1 voltage is within the normal operating voltage range. |
• | Passenger frontal deployment loop is not shorted to voltage. |
• | Passenger frontal high terminal A3 of connector C1 is less than 2 volts. |
Deployment loop resistance measurement test:
• | Ignition 1 voltage is within the normal operating voltage range. |
• | Passenger frontal deployment loop is not shorted to voltage. |
• | Passenger frontal deployment loop is not shorted to ground. |
Deployment loop voltage out of range test - Passenger frontal deployment loop resistance is at least 6 ohms for 300 milliseconds.
Deployment loop resistance measurement test - Passenger frontal deployment loop resistance is more than 3.7 ohms for 300 milliseconds.
The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.
• | You can issue a CLEAR CODES command |
• | A history DTC will clear once 255 malfunction free ignition cycles have occurred |
The following can cause an intermittent condition:
• | The inflatable restraint IP module yellow 2-way connector. |
• | The 4-way inline connector C218. |
• | The SDM wiring harness connector C1. |
• | The wire to terminal connections in the passenger frontal high circuit. |
• | The wire to terminal connections in the passenger frontal low circuit. |
• | Refer to cell-id="62112">Testing for Intermittent and Poor Connections> in Wiring Systems. |
The number(s) below refer to the step number(s) on the diagnostic table.
This step checks the inline connector C218.
This step isolates the malfunction to one side of inline connector C218.
This step checks the inflatable restraint IP module yellow 2-way connector.
This step determines if there is an open or high resistance in either the passenger frontal high or the passenger frontal low circuits in the wiring harness between the inflatable restraint IP module yellow 2-way connector and inline connector C218 or if there is a malfunctioning inflatable restraint IP module.
This step checks the SDM wiring harness connector C1.
This step checks to see if there is an open or a high resistance in the passenger frontal high circuit in the wiring harness between inline connector C218 and the SDM wiring harness connector C1.
This step determines if there is an open or high resistance in the passenger frontal low circuit in the wiring harness between inline connector C218 and the SDM wiring harness connector or if there is a malfunctioning SDM.
Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform A Diagnostic System Check - SIR? | -- | Go to Step 2 | Go to cell-id="57882">A Diagnostic System Check - SIR> | ||||||
Does either the male or female side of inline connector C218 exhibit any signs of corrosion, terminal damage, or poor connections? | -- | Go to Step 3 | Go to Step 4 | |||||||
3 |
Did you complete the repair? | -- | Go to Step 18 | -- | ||||||
4 |
Does the scan tool indicate that this DTC is current? | -- | Go to Step 5 | Go to Diagnostic Aids | ||||||
Does the scan tool indicate that this DTC is current? | -- | Go to Step 11 | Go to Step 6 | |||||||
Does either the component or harness side of the inflatable restraint IP module yellow 2-way connector exhibit any signs of corrosion, terminal damage, or poor connections? | -- | Go to Step 7 | Go to Step 8 | |||||||
7 |
Did you complete the repair? | -- | Go to Step 18 | -- | ||||||
Does the scan tool indicate that this DTC is current? | -- | Go to Step 9 | Go to Step 10 | |||||||
9 |
Did you complete the repair? | -- | Go to Step 18 | -- | ||||||
10 |
Did you complete the replacement? | -- | Go to Step 18 | -- | ||||||
Does the SDM wiring harness connector exhibit any signs of corrosion, terminal damage, or poor connections? | -- | Go to Step 12 | Go to Step 13 | |||||||
12 | Replace the SDM wiring harness connector. Refer to cell-id="61973">Connector Repairs> in Wiring Systems. Did you complete the repair? | -- | Go to Step 18 | -- | ||||||
Does the resistance measure less than the specified value? | 0.5 ohms | Go to Step 15 | Go to Step 14 | |||||||
14 | Locate and repair the open or high resistance in the passenger frontal high circuit in the wiring harness between the inline connector C218 and the SDM wiring harness connector. Refer to cell-id="62194">Circuit Testing> and cell-id="61965">Wiring Repairs> in Wiring Systems. Did you complete the repair? | -- | Go to Step 18 | -- | ||||||
Use the DMM to measure the resistance of the passenger frontal low circuit in the wiring harness between the 4-way inline connector C218 and the SDM wiring harness connector. Does the resistance measure less than the specified value? | 0.5 ohms | Go to Step 17 | Go to Step 16 | |||||||
16 | Locate and repair the open or high resistance in the passenger frontal low circuit in the wiring harness between the inline connector C218 and the SDM wiring harness connector. Refer to cell-id="62194">Circuit Testing> and cell-id="61965">Wiring Repairs> in Wiring Systems. Did you complete the repair? | -- | Go to Step 18 | -- | ||||||
17 | Replace the SDM. Refer to cell-id="57768">Inflatable Restraint Sensing and Diagnostic Module Replacement> or cell-id="57768">Inflatable Restraint Sensing and Diagnostic Module Replacement> . Did you complete the replacement? | -- | Go to Step 18 | -- | ||||||
18 |
Did you complete the action? | -- | Go to cell-id="57882">A Diagnostic System Check - SIR> | -- |