GM Service Manual Online
For 1990-2009 cars only

Circuit Description (Domestic)

DTC B3069 may be caused by the key cylinder unlock switch or key cylinder unlock switch circuit. The switch, which is contained within the driver door lock actuator, and circuit are part of the Central Door Unlock feature. The driver door module (DDM) supplies battery voltage to the key cylinder unlock switch, via the key cylinder unlock signal circuit, and ground via the ground circuit. The key cylinder unlock switch is operated by a mechanical linkage rod that is connected to the driver door lock cylinder mounted in the driver door.

The key cylinder unlock switch is normally in the open state and is closed by inserting the door key into the driver door lock cylinder and turning to the UNLOCK position. If the driver door lock cylinder is held to the UNLOCK position for 3 seconds or longer, or, turned to the UNLOCK position twice within 3 seconds, the DDM detects the flow of voltage through the key cylinder unlock switch as an input signal to unlock all doors. The DDM sends a serial data class 2 request to unlock all doors to the rear integration module (RIM), which is the master of all lock/unlock operations. If the RIM determines that conditions are correct for all doors to be unlocked, it sends a serial data class 2 message back to each door module to unlock all doors. All doors then simultaneously unlock.

Circuit Description (Export)

DTC B3064 may be caused by the key cylinder lock switch or key cylinder lock switch circuit. The switch, which is contained within the driver door lock actuator, and circuit are part of the Central Door Lock feature. The DDM supplies battery voltage to the key cylinder lock switch, via the key cylinder lock signal circuit, and ground via the ground circuit. The key cylinder lock switch is operated by a mechanical linkage rod that is connected to the driver door lock cylinder mounted in the driver door.

The key cylinder lock switch is normally in the open state and is closed by inserting the door key into the driver door lock cylinder and turning to the LOCK position. The DDM detects the flow of voltage through the key cylinder lock switch as an input signal to lock all doors. The DDM sends a serial data class 2 request to lock all doors to the RIM, which is the master of all lock/unlock operations. If the RIM determines that conditions are correct for all doors to be locked, it sends a serial data class 2 message back to each door module to lock all doors. All doors then immediately lock.

On export vehicles that also have the door lock deadbolt feature, if the driver door lock cylinder is held to the LOCK position for 3 seconds or longer or turned to the LOCK position twice within 3 seconds, all doors will also deadbolt. When the doors are deadbolted, they cannot be manually unlocked.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B3064 Right Front/Left Front Door Key Lock Switch Circuit Low
    • DTC B3069 Right Front/Left Front Door Key Unlock Switch Circuit Low

Conditions for Running the DTC

The DDM must be powered and can not have B1327 Battery Voltage Low or B1328 Battery Voltage High set for the DTC to set.

Conditions for Setting the DTC

If the DDM detects that the key cylinder unlock switch circuit is closed for more than 30 continuous seconds on a domestic vehicle, it sets DTC B3069.

If the DDM detects that the key cylinder lock switch circuit is closed for more than 30 continuous seconds on a export vehicle, it sets DTC B3064.

Action Taken When the DTC Sets

The DDM ignores signal inputs from this switch and stops sending messages to the RIM for it.

Conditions for Clearing the DTC

The DDM clears this DTC when the switch signal is no longer received, or when the vehicle ignition status changes from OFF to RUN.

Diagnostic Aids

An intermittently sticking key cylinder switch can cause this DTC to set. Refer to Testing for Electrical Intermittents in Wiring Systems.

For more information on Central Door Unlock, Central Door Lock, deadbolting, and the key cylinder switches, refer to Power Door Locks Description and Operation .

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

Connector End View Reference: Power Door Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Key Cylinder Lock/Unlock parameter in the Driver Door Module, Inputs list.

Does the scan tool display Idle?

Go to Step 3

Go to Step 4

3

  1. If the vehicle is a domestic vehicle, insert the door key into the driver door lock cylinder, turn and hold it to the UNLOCK position for 3 seconds or longer.
  2. If the vehicle is an export vehicle, insert the door key into the driver door lock cylinder, turn and hold it to the LOCK position for 3 seconds or longer.
  3. With the scan tool, observe the Key Cylinder Lock/Unlock parameter.

Does the Key Cylinder Lock/Unlock parameter change to the appropriate state?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the driver door lock actuator harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Key Cylinder Lock/Unlock parameter.

Does the scan tool display Idle?

Go to Step 7

Go to Step 5

5

Test the appropriate key cylinder switch signal circuit 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 driver door module (DDM) harness connector. 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 driver door lock actuator harness connector. 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

Important: Perform the setup procedure for the replacement door module. Refer to Door Control Module Programming and Setup .

Replace the DDM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

9

Replace the driver door lock actuator. Refer to Front Side Door Latch 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