Hummer H2. Manual - part 502

DTC B3809

Circuit Description

The Body Control Module (BCM) internally grounds the door unlock relay control circuit for the rear door
unlock relay when it receives a Class 2 message from the Driver Door Module (DDM) or Passenger Door
Module (PDM). When the BCM grounds the door unlock relay control circuit the rear door unlock relay is
energized and unlocks the rear doors.

Conditions for Running the DTC

Refer to Circuit Testing and Wiring Repairs in
Wiring Systems.
Did you complete the repair?

Go to Step 14

Go to Step 11

Inspect for poor connections at the rear door lock
relay. 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 13

Go to Step 12

Inspect for poor connections at the harness
connector of the body 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 14

Go to Step 13

Repair the short to ground in the door lock actuator
lock or unlock circuits. Refer to Wiring Repairs in
Wiring Systems.
Did you complete the repair?

Go to Step 14

Replace the rear door lock relay.
Did you complete the replacement?

Go to Step 14

Replace the body control module. Refer to Body
Control Module Replacement in Body Control
System.Did you complete the replacement?

IMPORTANT:

Perform the set up procedure for the body
control module.

Go to Step 14

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

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Doors - Hummer H2

Battery voltage is between 9.0-16.0 volts.

The DTC will set if the rear door unlock function is active or inactive.

Conditions for Setting the DTC

The DTC will set if the door unlock relay control circuit is shorted to ground or open for more then one second.

Action Taken When the DTC Sets

If a short to ground is present on the door unlock relay control circuit, the door unlock relay will be
energized and the rear door lock actuators will be held in the unlock position and will not lock.

If an open condition is present on the door unlock relay control circuit, the rear doors will lock but not
unlock.

Diagnostic Aids

DTC B3809 could also set if the door unlock relay winding is open.

If both DTC B3808 and B3809 are set as current, the battery positive voltage circuit or the LOCKS fuse
could be open. If the LOCKS fuse is open, the cause is most likely one of the following:

{

A short to ground in the relay battery positive voltage circuit.

{

A short to ground in the door lock actuator lock or unlock control circuits.

Conditions for Clearing the DTC

When the fault is no longer present, the BCM changes the current DTC to a history DTC. The BCM will clear
the history DTC after 50 fault free ignition cycles.

Test Description

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

2: Listen for an audible click when the rear door unlock relay operates. Command both the ON and OFF
states. Repeat the commands as necessary.

3: Tests for voltage at the coil side of the rear door unlock relay. The LOCKS fuse supplies power to the
coil side of the rear door unlock relay.

4: Verifies that the body control module is providing ground to the rear door unlock relay.

5: Tests if ground is constantly being applied to the rear door unlock relay.

DTC B3809

Step

Action

Yes

Schematic Reference: Door Lock/Indicator Schematics
Connector End View Reference:Power Door Systems Connector End Views

Did you perform the Door Systems Diagnostic
System Check?

Go to Diagnostic

System Check -

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Doors - Hummer H2

Go to Step 2

Door Systems

1. Install a scan tool.

2. With a scan tool, command the rear door

unlock relay ON and OFF.

Does the rear door unlock relay turn ON and OFF
with each command?

Go to Testing for

Intermittent Conditions

and Poor Connections in

Wiring Systems

Go to Step 3

1. Remove the rear door unlock relay.

2. Probe the battery positive voltage circuit of

the rear door unlock relay with a test lamp
that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 8

1. Connect a test lamp between the door unlock

relay control circuit and the battery positive
voltage circuit of the rear door unlock relay.

2. With a scan tool, command the rear door

unlock relay ON and OFF.

Does the test lamp turn ON and OFF with each
command?

Go to Step 9

Go to Step 5

Does the test lamp remain illuminated without
being commanded?

Go to Step 7

Go to Step 6

Test the door unlock relay control circuit of the rear
door unlock relay for an open. Refer to Circuit
Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 14

Go to Step 10

Test the door unlock relay control circuit of the rear
door unlock relay for a short to ground or an open.
Refer to Circuit Testing and Wiring Repairs in
Wiring Systems.
Did you find and correct the condition?

Go to Step 14

Go to Step 10

Test for an open or short to ground in the battery
positive voltage circuit of the rear door unlock
relay. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?

Go to Step 14

Go to Step 11

Inspect for poor connections at the rear door unlock
relay. 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 14

Go to Step 12

Inspect for poor connections at the harness
connector of the body control module. Refer to
Testing for Intermittent Conditions and Poor

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Doors - Hummer H2

DTC B3819

Circuit Description

The Body Control Module (BCM) grounds the control side of the left rear power window up relay upon
receiving a class 2 message from the Driver Door Module (DDM).

Conditions for Running the DTC

Battery voltage is between 9.0 and 16 volts.

The BCM has received a class 2 message from the DDM and has grounded the left rear power window
relay control circuit.

Conditions for Setting the DTC

When the BCM has grounded the left rear power window up relay control circuit and the control circuit is
shorted to battery positive voltage.

The above condition is met for 250 milliseconds.

Action Taken When the DTC Sets

The left rear power window will be inoperative from both the driver and left rear power window switches.

Connections and Connector Repairs in Wiring
Systems.
Did you find and correct the condition?

Go to Step 14

Go to Step 13

Repair the short to ground in the door lock actuator
lock or unlock control circuits. Refer to Wiring
Repairs in Wiring Systems.
Did you complete the repair?

Go to Step 14

Replace the rear door unlock relay.
Did you complete the replacement?

Go to Step 14

Replace the body control module. Refer to Body
Control Module Replacement in Body Control
System.Did you complete the replacement?

IMPORTANT:

Perform the set up procedure for the body
control module.

Go to Step 14

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

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Doors - Hummer H2

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