B0022

DTC B0022, B0024, or B0026









CIRCUIT DESCRIPTION
The inflatable restraint steering wheel module deployment loop consists of a steering wheel module, steering wheel module coil, steering wheel module high signal circuit, and steering wheel module low signal circuit. Shorting bars are used on the steering wheel module connector as well as the steering wheel module coil connector which will short together the steering wheel module high and steering wheel module low signal 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 DTC will be stored.

CONDITIONS FOR RUNNING THE DTC
Ignition 1 voltage is within the normal operating voltage range.

CONDITIONS FOR SETTING THE DTC
DTC B0022 will set when the steering wheel module deployment loop resistance is less than 1.3 ohms for 500 milliseconds.

DTC B0024 will set when one of the following conditions occurs:
- The SDM detects the voltage at steering wheel module high signal is greater than 6 volts for 500 milliseconds.
- The SDM detects the voltage at steering wheel module high signal is less than 2.4 volts and steering wheel module deployment loop resistance is less than 6 ohms for 500 milliseconds.

DTC B0026 will set when one of the following conditions occurs:
- The SDM detects the steering wheel module deployment loop resistance is greater than 4.8 ohms for 500 milliseconds.
- The SDM detects the voltage at steering wheel module high signal is less than 2.4 volts and steering wheel module deployment loop resistance is 6 ohms or greater for 500 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
The SDM commands ON the AIR BAG indicator 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 steering wheel module high and steering wheel module low signal circuits.
- A malfunctioning shorting bar on the steering wheel module connector.
- A malfunctioning shorting bar on the steering wheel module coil connector.

Refer to Testing for Intermittent Conditions and Poor Connections.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. Inspects the steering wheel module coil in-line connector.
5. Tests for a malfunctioning steering wheel module.
7. If DTC B0022 is present, test for a short between the steering wheel module high and steering wheel module low signal circuits. If DTC B0024 is present, test for a short to ground or voltage in the steering wheel module high and steering wheel module low signal circuits. If DTC B0026 is present, test for an open or high resistance in the steering wheel module high and steering wheel module low signal circuits.