Circuit Description
When you first turn ON the ignition, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. Next the SDM measures IGNITION 1 and the deployment loop voltages to make sure they are within their respective normal voltage ranges. Then the SDM proceeds with the resistance measurement test. During one portion of the resistance measurement test, the SDM does the following:
| • | Grounds the passenger side low circuit through an internal circuit sink. |
| • | Connects the passenger side high circuit to an internal constant current source. This current produces proportional voltage drops in the deployment loop. |
| • | Measures the voltage difference between the passenger side high circuit and the passenger side low circuit. |
| • | Calculates the resistance of the passenger deployment loop using the measured voltage. |
Conditions for Running the DTC
| • | The driver and passenger deployment loops are not open. |
| • | The driver and passenger deployment loops are not shorted to voltage. |
| • | The passenger deployment loop is not shorted to ground. |
Conditions for Setting the DTC
The passenger deployment loop resistance is more than 3.0 ohms.
The resistance measurement test checks for this malfunction. This test only occurs once each ignition cycle when IGNITION 1 is within the normal operating voltage range.
Action Taken When the DTC Sets
The SDM commands ON the AIR BAG warning lamp.
Conditions for Clearing the DTC
| • | The resistance of the passenger deployment loop is less than 3.0 ohms and the ignition switch is cycled. |
| • | You can issue a CLEAR CODES command. |
| • | A history DTC will clear once 255 malfunction free ignition cycles have occurred. |
Diagnostic Aids
A poor connection can cause and intermittent condition. Check the following for a poor connection:
| • | The inflatable restraint IP module yellow connector. |
| • | The SDM wiring harness yellow connector. |
| • | The wire to terminal connections in the passenger side high circuit. |
| • | The wire to terminal connections in the passenger side low circuit. |
The diagnostic table directs the technician to note the entry value of passenger resistance. Comparing the value of PASSENGER RESISTANCE over multiple ignition cycles can be helpful in determining if an intermittent condition exists.
When measurements are requested in this table, use the J 39200 DMM with the correct terminal adapter from the J 35616 Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Testing for Electrical Intermittents in Wiring Systems. When a wire, connector or terminal repair is requested, use the J-38125 Terminal Repair Kit and refer to Wiring Repairs in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This step checks the passenger deployment loop resistance that was measured by the inflatable restraint sensing and diagnostic module (SDM).
-
This step checks to see if the inflatable restraint IP module yellow 2-way connector is corroded or damaged.
-
This step isolates the malfunction to one side of the inflatable restraint IP module yellow 2-way connector.
-
This step checks the SDM wiring harness connector for corrosion or damaged terminals.
-
This step checks to see if there is a high resistance in the passenger side high circuit.
-
This step determines if there is a high resistance in the passenger side low circuit or if there is a malfunctioning SDM.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the SIR Diagnostic System Check? | -- | ||
Has the PASSENGER RESISTANCE been read and recorded on the repair order? | -- | -- | ||
Are the terminals damaged or corroded? | -- | |||
4 | Replace the inflatable restraint IP module yellow 2-way wiring harness connector. Refer to Connector Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
5 | Check for a proper connection at the inflatable restraint IP module yellow 2-way connector. Are the terminals damaged or corroded? | -- | ||
6 | Check for a proper connection at the inflatable restraint IP module yellow 2-way connector. Are the terminals damaged or corroded? | -- | ||
7 | Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement . Did you complete the repair? | -- | -- | |
8 |
Is the PASSENGER RESISTANCE more than the specified value? | 3.0 ohms | ||
9 |
Did you complete the repair? | -- | -- | |
Is the PASSENGER RESISTANCE more than the specified value? | 3.0 ohms | |||
11 |
Did you complete the repair? | -- | -- | |
Is the SDM wiring harness connector damaged or corroded? | -- | |||
13 | Replace the SDM wiring harness connector. Refer to Connector Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
14 | Check for a proper connection at the passenger side high circuit and the passenger side low circuit of the SDM. Are the SDM terminals damaged or corroded? | -- | ||
15 | Check for a proper connection at the passenger side high circuit and the passenger side low circuit of the SDM. Are the SDM terminals damaged or corroded? | -- | ||
16 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the repair? | -- | -- | |
Is the measured resistance within the specified value? | 0-0.5 ohms | |||
18 |
Did you complete the repair? | -- | -- | |
Use the J 39200 to measure the resistance of the passenger side low circuit between the wiring harness yellow SDM connector and the inflatable restraint IP module yellow 2-way wiring harness connector. Is the measured resistance within the specified value? | 0-0.5 ohms | |||
20 |
Did you complete the repair? | -- | -- | |
21 |
Did you complete the action? | -- | -- |
