B2221

DTC B2221 LF Door Lock/Unlock Switch Stuck Unlock:

CIRCUIT DESCRIPTION
The LH front power door lock switch feeds switch signals to the LH front power window switch over CKT 780 (RED/BLK) and CKT 781 (ORN/BLK). The LH front power window switch convents the switch inputs to serial digital data and broadcasts the message out on the simple bus interface. The simple bus interface, CKT 217 (LT BLU), provides a communications path from the driver's door switch to the Driver's Door Module (DDM). The DDM contains the following two types of software:
^ Switch message decoding software
^ Simple bus interface diagnostic software

The software enables the DDM to accept messages from the door switch and test the interface between the two components.

CONDITIONS FOR SETTING THE DTC
^ If either of the switch inputs for LOCK or UNLOCK remain closed continuously for 30 seconds, DTC B2221 sets.
^ DTCs B1982 (Battery Voltage High) and B1983 (Battery Voltage Low) must not be current or the diagnostic will not run.

ACTION TAKEN WHEN THE DTC SETS
The switch actuation will be ignored until the switch leaves the low state change of the lock switch input. The manual door lock levers and key locks will still function normally.

CONDITIONS FOR CLEARING THE MIL/DTC
^ This DTC will set from current to history when the UNLOCK input cycles oft or when the power mode changes from OFF to RUN.
^ The history DTC will clear after 50 ignition cycles.
^ Use a scan tool in order to clear the history DTC.

DIAGNOSTIC AIDS
The scan tool can be selected to monitor DDM inputs and set outputs as well as view DTCs. The scan tool may also used to select Remote Function Actuator (RFA) inputs, outputs and options.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
1. Perform the Power Door Diagnostic System check prior to diagnosing DTC B2221
2. This test step checks for the LH front power door lock switch failing mechanically
3. This test step checks for inputs to the Driver Door Module
4. This test step tests the LH front power door lock switch
7. This test step tests circuit 781 for a short to ground