GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2002 🢒 DeVille 🢒 DTC 🢒 DTC B3064 or B3069

Circuit Description

The switch that failed and generated this diagnostic trouble code (DTC) is mounted to the inside of the driver door key cylinder and wired to the driver door module (DDM). The normally open switch is closed when the key is inserted into the driver door lock cylinder and turned to the Unlock position. When the DDM senses that the driver door key cylinder unlock switch has been turned to the Unlock position and held for 3 seconds or longer, or, turned to the Unlock position twice within 3 seconds, it sends a Serial Data Class 2 message to the rear integration module (RIM) to unlock the doors. The RIM is the master of all lock operations. If the RIM determines that the Unlock request is a valid request and conditions are correct for the doors to be Unlocked, it sends its OK back to each door module to unlock the doors.

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 this DTC to set.

Conditions for Setting the DTC

If the DDM, detects that the circuit is closed for more than 30 continuous seconds in the Unlock position, it sets the DTC.

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 during, or when the vehicle ignition status changes from OFF to Run.

Diagnostic Aids

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

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 Key Cylinder Unlock parameter in the Driver Door Module Inputs data list.

Does the scan tool display OFF?

Go to Step 3

Go to Step 4

3
  1. Insert the door key into the driver door lock cylinder, turn and hold it to the Unlock position for 3 seconds or longer.
  2. With the scan tool, observe the Key Cylinder Unlock parameter.

Does the Key Cylinder Unlock parameter change state?

Go to Diagnostic Aids

Go to Step 4

4
  1. Turn OFF the ignition.
  2. Disconnect the driver door key cylinder unlock switch harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Key Cylinder Unlock parameter.

Does the scan tool display OFF?

Go to Step 7

Go to Step 5

5

Test the driver door key cylinder unlock 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 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 key cylinder unlock switch 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

Replace the driver door control module. Refer to Door Control Module Replacement .

Did you complete the replacement?

Go to Step 10

--

9

Replace the driver door key cylinder unlock switch. Refer to Door Lock Cylinder 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