B3593

DTC B3593

Circuit Description
The rear wheel steering control module monitors the rear wheel steering mode select switch 5-volt reference circuit for out of range voltage conditions. When the mode select switch button is depressed the switch is in the active state. When the mode select switch is released the switch is in the inactive state. The following conditions will help determine if there is a malfunctioning rear wheel steering mode select switch:
^ The resistance of the load in the active state is 500 ohms with an additional 1,000 ohms pull-up resistor.
^ The resistance of the load in the inactive state is 2,000 ohms with an additional 1,000 ohms pull-up resistor.
^ The pull-up voltage is 12 volts.

Conditions for Running the DTC
Turn ON the ignition, with engine ON.

Conditions for Setting the DTC
^ The mode select switch 5-volt reference circuit is open, shorted to ground or voltage.
^ The mode select switch signal circuit is open or shorted to voltage.

Action Taken When the DTC Sets
^ The Service 4-Wheel Steer indicator on IPC will be displayed.
^ The code is displayed on the scan tool as DTC B3593.
^ The output to the motor is ramped down slowly at a rate of 1 degree/second back to center and held.
^ The rear wheels will be returned to the centered position.

Conditions for Clearing the DTC
^ The conditions for DTC are not currently present.
^ The module receives a clear code command from the scan tool.
^ The DTC clears after 100 malfunction free ignition cycles.

Diagnostic Aids
^ Inspect for poor connections at the harness connector of the rear wheel steering control module and Rear Wheel Steering Select Switch.
^ Observe the rear wheel steering mode select switch. If all of the mode indicator LEDs are illuminated the rear wheel steering control module has lost its alignment memory settings and the scan tool must be used to re-calibrate the rear wheel steering alignment data in the rear wheel steering control module.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. The normal state of the switch is the state of the switch input before activation. The terminology used by the scan tool is OFF.
3. Tests for the proper operation of the switch in the normally open position.
4. Tests for the proper operation of the switch in the closed position.
8. Tests the 5-volt reference circuit for an open or a short to ground.

Steps 1 - 9:

Steps 10 - 15:

DTC B3593