Circuit Description
The left front power door lock switch feeds switch signals to the left front power window switch over CKT 780 (RED/BLK) and CKT 781 (ORN/BLK). The left front power window switch converts 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 driver's door module 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 door lock switch input cycles OFF or the power mode changes from OFF to RUN. |
| • | The history DTC will clear after 50 consecutive 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.
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Perform the Power Door Diagnostic System check prior to diagnosing DTC B2221
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This test step checks for the left front power door lock switch failing mechanically
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This test step checks for inputs to the DDM
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This test step tests the left front power door lock switch
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This test step tests circuit 781 for a short to ground
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Has the Power Door Diagnostic System Check been performed? | -- | Go to Step 2 | |
2 | Is the right front power door lock switch mechanically stuck in the lock or unlock position? | -- | Go to Step 5 | Go to Step 3 |
3 |
Go to driver door module (DDM) inputs. Does the right front door lock switch display lock or unlock? | -- | Go to Step 4 | Go to Step 6 |
4 |
Move the door lock switch to the UNLOCK position. Connect a DMM across the power lock switch terminals B and C. Move the door lock switch to the LOCK position. Is the resistance within the specified range for both switch positions? | 0-5ohms | Go to Step 7 | Go to Step 5 |
5 | Replace the right front power door lock switch. Refer to Door Lock Switch Replacement . Is the repair complete? | -- | Go to Step 10 | -- |
6 | Replace the driver door module (DDM). Refer to Front Door Module Replacement . Is the repair complete? | -- | Go to Step 10 | -- |
7 | Test CKT 781 (ORN/BLK) for a short to ground. Is the circuit OK? | -- | Go to Step 9 | Go to Step 8 |
8 | Repair the short to ground in CKT 781 (ORN/BLK) Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 10 | -- |
9 | Replace the left front power window switch. Refer to Front Side Door Window Switch Replacement . Is the repair complete? | -- | Go to Step 10 | -- |
10 |
Are all the DTCs cleared? | -- | -- |
