GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2003 🢒 Park Avenue 🢒 Body and Accessories 🢒 Doors 🢒 DTC B2220-B2224, or B2226

Circuit Description

The lock switch or lock switch circuit that failed and generated this diagnostic trouble code (DTC) is wired to either the driver door switch assembly (DDSA), or the front passenger door module (PDM). The DDSA and the PDM supply voltage to the contacts of both the Lock and Unlock signal circuits of their respective lock switch. The DDSA and the PDM also supply a ground to their associated lock switch. When the normally open contacts of one of the switches are closed to ground, the associated door module interprets this switch signal and converts it to a digital message, which is then sent, via the power door serial data circuit, to the driver door module (DDM). The DDM sends the switch message to the rear integration module (RIM), which is the "master" of all lock operations, as a Class 2 message. The RIM checks all other vehicle information sent out over the Class 2 serial data line to determine if vehicle conditions are correct for a Lock or Unlock request to be performed. If conditions are correct, the RIM sends its OK to the DDM via Class 2. When the OK message is received, the DDM sends the required signal to all other door modules via the power door serial data line.

Conditions for Running the DTC

The DDM and PDM must be powered, in communications with each other and can not have B1327-Battery Voltage Low or B1328-Battery Voltage High set for these DTCs to set.

Conditions for Setting the DTC

If the DDM receives the message that either a passenger door lock switch circuit is closed to ground for more than 30 continuous seconds or a DDSA lock switch circuit is closed to ground for more than 255 seconds (4.25 minutes), the DDM sets a lock switch circuit DTC.

Action Taken When the DTC Sets

The DDM ignores any message from the lock switch designated by the DTC and prevents lock movement from the switch. The DDM will respond to other lock switch messages.

Conditions for Clearing the DTC

The DDM clears this current DTC when the switch message is no longer received and stores a history DTC. The history DTC will clear either after 50 OFF/ON ignition switch cycles without a repeated failure or in response to a scan tool command.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step checks the module input state using the normal input status.

    2.

  2. This step checks to see that the input is seen by the module.

    3.

  3. This step checks to see that the signal lines to the module are open with the switch removed.

    4.

  4. This step determines if the signal circuits are shorted.

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

1

Did you perform the Door Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Door Systems

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Driver Door Lock Switch or the Pass. Door Lock Switch parameter for the appropriate door in the driver door module (DDM) Inputs list.

Does the scan tool display Idle?

Go to Step 3

Go to Step 4

3

  1. Activate the appropriate door lock switch.
  2. With the scan tool, observe the Driver Door Lock Switch or the Pass. Door Lock Switch parameter for the appropriate door.

Does the door lock switch parameter change state?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the appropriate door lock switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Driver Door Lock Switch or the Pass. Door Lock Switch parameter for the appropriate door.

Does the scan tool display Idle?

Go to Step 7

Go to Step 5

5

Test the signal circuits of the appropriate door lock switch for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

Inspect for poor connections at the harness connector of the appropriate door control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 8

7

Inspect for poor connections at the harness connector of the appropriate door lock switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

8

Replace the appropriate door control module. Refer to Door Control Module Replacement - Front .

Did you complete the replacement?

Go to Step 10

--

9

Replace the appropriate door lock switch. Refer to Door Lock Switch Replacement .

Did you complete the replacement?

Go to Step 10

--

10
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK