B0018

DTC B0018

CIRCUIT DESCRIPTION
The passenger deployment loop consists of an inflatable restraint instrument panel module (IPM), the IPM high and IPM low circuits. There is a shorting bar used within the IPM connector which will short together both IPM 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 IPM. 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 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 B0016 will set when the IPM deployment loop resistance is less than 1.3 ohms for 500 milliseconds.
- DTC B0017 will set when one of the following conditions occurs:
- The IPM high circuit is less than 2.4 volts and the IPM deployment loop is more than 6 ohms for 500 milliseconds.
- The IPM deployment loop resistance is more than 4.8 ohms for 500 milliseconds.
- DTC B0018 will set when one of the following conditions occur:
- The IPM high and/or low circuits are short to ground or short to voltage for 500 milliseconds.
- The IPM high circuit is less than 2.4 volts and the IPM 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 IPM high and low circuits
- An open or a high resistance in the IPM high or low circuits
- A short to ground or a short to voltage in the IPM high or low circuits
- The IPM connector
- The SDM connector
- A malfunctioning IPM
- 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 1-9:

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 IPM.
6. This step tests to see what DTCs are present. If DTC B0016 is present, test the IPM for a short between high and low circuits. If DTC B0017 is present, test the IPM high and low circuits for an open and for high resistance. If DTC B0018 is present, test the IPM high and low circuits for a short to ground and for a short to voltage.