B0018

DTC B0018

CIRCUIT DESCRIPTION




The passenger frontal deployment loop consists of the following components:
- A dual stage inflatable restraint instrument panel (I/P) module
- The I/P high circuits for both stages 1and 2
- The I/P low circuits for both stages 1and 2

There are 2 shorting bar used within the I/P connector which will short together both I/P stage 1 high and low circuits and both I/P stage 2 high and low circuits when the connector is disconnected, this will help to prevent unwanted deployment of the inflator module during servicing. During a frontal crash of sufficient force the inflatable restraint sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy the I/P. The 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 DTC will be stored in memory.

DTC DESCRIPTORS
This diagnostic procedure supports the following DTCs:
- DTC B0012 Passenger Frontal Deployment Loop (stage 2) Resistance Low
- DTC B0013 Passenger Frontal Deployment Loop (stage 2) Open
- DTC B0014 Passenger Frontal Deployment Loop (stage 2) Voltage Out of Range
- DTC B0016 Passenger Frontal Deployment Loop (single stage or stage 1) Resistance Low
- DTC B0017 Passenger Frontal Deployment Loop (single stage or stage 1) Open
- DTC B0018 Passenger Frontal Deployment Loop (single stage or stage 1) 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 I/P 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:
- I/P high circuit is less than 2.4 volts and the I/P deployment loop is more than 6 ohms for 500 milliseconds.
- I/P deployment loop resistance is more than 4.8 ohms for 500 milliseconds.
- DTC B0014 - stage 2 or B0018 - stage 1 will set when one of the following conditions occur:
- I/P high and/or low circuits is short to ground or short to voltage for 500 milliseconds.
- I/P high circuit is less than 2.4 volts and I/P 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 and the scan tool Clear DTCs function is used.
- A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

DIAGNOSTIC AIDS
The following are possible causes of the malfunction:
- A short between the I/P stage 1 or stage 2, high and low circuits
- An open or a high resistance in the I/P stage 1 or stage 2, high or low circuits
- A short to ground or a short to voltage in the I/P stage 1 or stage 2, high or low circuits
- The I/P connector
- The SDM connector
- A malfunctioning I/P
- A malfunctioning SDM

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-6:

Steps 7-9:

The numbers below refer to the step numbers on the diagnostic table.
4. This step tests to see if the malfunction is caused by the I/P.
6. This step tests to see what DTCs are present. If DTC B0012 or B0016 is present, test for a short between the I/P high and low circuits in stage 1 or stage 2. If DTC B0013 or B0017 is present, test the I/P high and low circuits for an open and for high resistance in stage 1 or stage 2. If DTC B0014 or B0018 is present, test the I/P high and low circuits for a short to ground and for a short to voltage in stage 1 or stage 2.