GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2006 🢒 Lucerne 🢒 DTC 🢒 DTC B3826

Circuit Description

The liftgate key cylinder switch provides a ground input to the body control module (BCM) when the switch is closed. This input allows the BCM to detect when a key unlock request is received.

Conditions for Running the DTC

The BCM detects a fault on the circuit for more than 60 seconds.

Action Taken When the DTC Sets

The BCM stores DTC B3826 in memory.

Conditions for Clearing the DTC
    • The BCM no longer detects a fault on the signal circuit for the liftgate key unlock switch.
    • A history DTC will clear after 100 consecutive ignition cycles if the malfunction no longer exists.
    • A scan tool can be used to clear history and current DTCs.

Diagnostic Aids

The cause of the malfunction could be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Yes

No

Schematic Reference: Body Rear End Schematics

Connector End View Reference: Body Rear End Connector End Views and Computer/Integrating Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Liftgate Key Cylinder Unlock parameter in the body control module (BCM) data list.

Does the scan tool display inactive?

Go to Diagnostic Aids

Go to Step 3

3
  1. Turn OFF the ignition.
  2. Disconnect the liftgate key cylinder switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Liftgate Key Cylinder Unlock parameter.

Does the scan tool display inactive?

Go to Step 6

Go to Step 4

4

Test the signal circuit of the liftgate key cylinder unlock switch for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 5

5

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 7

6

Inspect for poor connections at the harness connector of the liftgate key cylinder switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 9

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8

Replace the decklid key cylinder switch. Refer to Rear Compartment Lid Latch Replacement .

Did you complete the replacement?

Go to Step 9

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9
  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