Circuit Description
The following diagnostics are designed to diagnose circuit failures for both single stage and dual stage air bag systems. The light duty G/H models are equipped with dual stage air bags and the heavy duty G/H models are equipped with single stage air bags. The inflatable restraint instrument panel (I/P) module deployment loop consists of an I/P module, I/P module high control, and I/P module low control circuits. There are shorting bars used within the I/P module connector which will short together the I/P module high and I/P module low control circuits when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module during servicing. When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a diagnostic trouble code (DTC) will be stored in memory.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B0012 RF/Passenger Frontal Deployment Loop (Stage 2) Resistance Low |
| • | DTC B0013 RF/Passenger Frontal Deployment Loop (Stage 2) Open |
| • | DTC B0014 RF/Passenger Frontal Deployment Loop (Stage 2) Voltage Out of Range |
| • | DTC B0016 Passenger Frontal Deployment Loop Resistance Low |
| • | DTC B0017 Passenger Frontal Deployment Loop Open |
| • | DTC B0018 Passenger Frontal Deployment Loop Voltage Out of Range |
Conditions for Running the DTC
Ignition 1 voltage is within the normal operating voltage range.
Conditions for Setting the DTC
| • | DTC B0012 - stage 2 or B0016 - stage 1 will set when the SDM detects the I/P module deployment loop resistance is less than 1.3 ohms for 500 milliseconds. |
| • | DTC B0013 - stage 2 or B0017 - stage 1 will set when one of the following conditions occurs: |
| - | The SDM detects the I/P module deployment loop resistance is greater than 4.8 ohms for 500 milliseconds. |
| - | The SDM detects the voltage at I/P module high control is less than 2.4 volts and I/P module deployment loop resistance is 6 ohms or greater for 500 milliseconds. |
| • | DTC B0014 - stage 2 or B0018 - stage 1 will set when one of the following conditions occurs: |
| - | The SDM detects the voltage at I/P module high control is shorted to ground or voltage for 500 milliseconds. |
| - | The SDM detects the voltage at I/P module high control is less than 2.4 volts and I/P module deployment loop resistance is less than 6 ohms for 500 milliseconds. |
Action Taken When the DTC Sets
The SDM commands the AIR BAG indicator ON via class 2 serial data.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | You issue a scan tool CLEAR DTCs command. |
| • | A history DTC will clear once 255 malfunction-free ignition cycles have occurred. |
Diagnostic Aids
The following can cause an intermittent condition:
| • | A short between the I/P module high and low control circuits |
| • | An open or a high resistance in the I/P module high or low control circuits |
| • | A malfunctioning shorting bar on the I/P module connector |
Refer to Testing for Intermittent Conditions and Poor Connections .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step inspects the I/P module in-line connector.
-
This step tests for a malfunctioning I/P module.
-
This step tests for current DTCs. If DTC B0012 or B0016 is present, test for a short between the I/P module high and I/P module low control circuits for stage 1 or stage 2. If DTC B0013 or B0017 is present, test for an open or high resistance in the I/P module high and I/P module low control circuits for stage 1 or stage 2. If DTC B0014 or B0018 is present, test for a short to ground or voltage in the I/P module high and I/P module low control circuits for stage 1 or stage 2.
Step | Action | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | |||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |||||||
Do the connectors exhibit any signs of corrosion, terminal damage, or poor connections? | Go to Step 3 | Go to Step 4 | |||||||
3 |
Did you complete the replacement? | Go to Step 9 | -- | ||||||
Important: When installing the J 38715-A Driver and Passenger SIR Load Tool for testing the dual stage I/P module, the correct 4-way load tool adapter must be used. Failure to use the correct 4-way load tool adapter will set additional codes when testing. Does the scan tool indicate that either DTC B0012, B0013, B0014, B0016, B0017, or B0018 is current? | Go to Step 5 | Go to Step 8 | |||||||
5 |
Did you find and correct the condition? | Go to Step 9 | Go to Step 6 | ||||||
Did you find and correct the condition? | Go to Step 9 | Go to Step 7 | |||||||
7 | Replace the SDM. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | Go to Step 9 | -- | ||||||
8 | Replace the I/P module. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | -- | ||||||
9 |
Does the DTC reset? | Go to Step 2 | System OK | ||||||
