B2220

DTC B2220 LF Door Lock/Unlock Switch Stuck in Lock:

CIRCUIT DESCRIPTION
The LH Front Power Door Lock Switch provides the LH Front seat occupant with the ability to initiate a lock all doors signal.

Whenever the Power Door Lock Switch is moved to the LOCK position, a ground is placed on the LH Front Power Window Switch Connector, terminal 7 input, through CKT 780 (RED/BLK).

The Power Door Lock Switch ground is provided from the LH Front Door Module via CKT 351 (BLK/WHT). If CKT 351 (BLK/WHT) is open or has a high resistance the LH Front power window will also exhibit problems. Splice S500 is the common ground point for both the Power Door Lock Switch and the Power Window Switch.

Power Window Switch power is furnished through CKT 640 (ORN). If CKT 640 (ORN) is open or shorted to ground, the LH Front power window will also exhibit problems.

hen this Power Door Lock Switch is placed in the LOCK position, the lock signal is sensed by the Power Window Switch, which then formats a digital message relating this switch activity. This digital message is then sent to the LH Front Door Module (LFDM) over the Simple Bus Interface (SBI). The LFDM relays this message to the Rear Interface Module (RIM), requesting a command to lock all doors. The RIM is the door lock master.

The RIM will check to see is the key is in the ignition and a door is open prior to sending a lock all doors command. Any problem with the SBI or LFDM will affect all door lock and window functions. Problems with the RIM will show up in a number of other subsystems including:
^ Rear Seat Heat
^ Theft
^ Courtesy Lamps
^ Park Brake
^ Rear Fog Lamp
^ Rear Defog
^ Release Systems
^ Rear Blower
^ Retained Accessory Power
^ Cigar Lighter

CONDITIONS FOR SETTING THE DTC
If the LOCK signal to the LH Front Power Window Switch remains grounded for a period of 30 seconds (calibrateable from 0 to 255 seconds), this DTC will become active (current). The LOCK signal from CKT 780 (RED/BLK) is examined by the LH Front Power Window Switch no less than once every 300 milliseconds.

The diagnostic for this DTC will not run if either DTC B1982 (Battery Voltage High) or B1983 (Battery Voltage Low) is set (current).

ACTION TAKEN WHEN THE DTC SETS
This DTC is dynamic, and as such, is set only while the fault is active. This switch actuation will be ignored by the door module until a switch change of state is detected.

CONDITIONS FOR CLEARING THE MIL/DTC
This DTC will automatically clear when the switch leaves the LOCK state.

DIAGNOSTIC AIDS
Enter SIO Table ID in servinfosub-sio Tag

TEST DESCRIPTION
Numbers below refer to the Diagnostic Table Step Number(s).
2. This step tests the LH front power door switch for an internal short.
5. This step tests CKT 780 for a short to ground.