Hummer H2. Manual — part 312

DTC B2610

Circuit Description

The body control module (BCM) receives a variable voltage signal from the instrument panel (I/P) dimmer

Systems.
Did you find and correct the condition?

Go to Step 13

Go to Step 9

7

Test the control circuit of the DRL relay 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 13

Go to Step 9

8

Inspect for poor connections at the DRL 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 11

9

Inspect for poor connections at the harness
connector of the BCM. 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

10

Repair the DRL supply voltage circuit of the DRL
relay. Refer to Wiring Repairs in Wiring
Systems.
Did you complete the repair?

Go to Step 13

-

11

Replace the DRL relay. Refer to Relay
Replacement (Within an Electrical Center)
Relay Replacement (Attached to Wire
Harness) in Wiring Systems.
Did you complete the replacement?

Go to Step 13

-

12 Replace the body control module (BCM). Refer to

Body Control Module Replacement in Body
Control System.Did you complete the
replacement?

IMPORTANT:

Perform the setup procedure for the BCM.

Go to Step 13

-

13

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 Lighting Systems - Hummer H2

switch requesting to illuminate the illumination lamps to a desired intensity. When this occurs, the BCM
directly sends a variable voltage based on the I/P dimmer switch position on the instrument panel lamps
dimming supply voltage circuit, controls illumination lamps dimming control circuit, and the LED dimming
signal circuit.

Voltage for the instrument panel lamps dimming supply voltage circuit, controls illumination lamps dimming
control circuit, and the LED dimming signal circuits is from the TBC 2 A fuse in the instrument panel fuse
block directly through the BCM to these circuits.

Conditions for Running the DTC

The battery voltage must be between 9.0-16.0 volts.

Conditions for Setting the DTC

z

The controls illumination lamps dimming control circuit is open, shorted to ground, or shorted to voltage.

z

The instrument panel lamps dimming supply voltage circuit is open, shorted to ground, or shorted to
voltage.

z

There is a loss of the instrument panel fuse block TBC 2 A battery supply voltage to the BCM for 1
second.

Action Taken When the DTC Sets

The illumination lamps will not operate or are always ON.

Conditions for Clearing the MIL/DTC

z

This DTC will clear on current status after the condition for setting the fault is corrected.

z

A history DTC will clear after 100 consecutive ignition cycles without a fault present.

z

History and current DTCs can be cleared using a scan tool.

Diagnostic Aids

z

Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for
Intermittent Conditions and Poor Connections in Wiring Systems.

z

A short to ground in the following circuits will cause the TBC 2 A fuse to open.

{

The controls illumination lamps dimming control.

{

Battery positive voltage from the instrument panel fuse block TBC 2 A fuse.

z

An open in the TBC 2 A fuse will cause the BCM to set the following DTC:

{

B0951

{

B2610

{

B2625

Test Description

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

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

5: This step test determines if the problem exists in the headlamp switch or the BCM.

10: After replacement of the BCM you must calibrate the new module for proper operation.

DTC B2610

Step

Action

Yes

No

Schematic Reference:Interior Lights Dimming Schematics
Connector End View Reference:Lighting Systems Connector End Views or Body Control System
Connector End Views in Body Control System

1

Did you perform the Lighting System Diagnostic System Check?

Go to

Step 2

Go to Diagnostic

System Check -

Lighting Systems

2

Is the TBC 2 A fuse in the instrument panel fuse block open?

Go to

Step 3

Go to Step 4

3

Test the controls illumination lamps dimming control 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

11

Go to Step 8

4

Test the instrument panel lamps dimming supply voltage circuit and
the controls illumination lamps dimming control circuit for an open,
high resistance, short to voltage or short to ground. Refer to Circuit
Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step

11

Go to Step 5

5

1. Ensure that the headlamp switch is in the on position.

2. Ensure that the instrument panel dimmer switch is the full bright

position.

3. With the headlamp switch still connected, connect a test lamp

between the controls illumination lamps dimming control circuit
and the ground circuit of the headlamp switch connector.

Does the test lamp illuminate?

Go to

Step 6

Go to Step 7

6

Inspect for poor connections at the harness connector of the headlamp
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

11

Go to Step 9

7

Inspect for poor connections at the harness connector of the BCM.
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

11

Go to Step 10

8

Repair the battery positive voltage circuit of the BCM from the TBC 2
A fuse in the instrument panel fuse block. Refer to Wiring Repairs in
Wiring Systems.
Did you complete the repair?

Go to

Step

11

-

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

DTC B2615

Circuit Description

The body control module (BCM) receives a ground signal from the door jamb, liftglass/liftgate if equipped, or
courtesy lamp switches requesting courtesy/dome lamp illumination. When this occurs, the BCM directly sends
a voltage through the courtesy lamp supply voltage circuit illuminating the courtesy/dome lamps.

Voltage for the courtesy lamp supply voltage circuit as well as the backup lamp supply voltage circuit is from
the left instrument panel fuse block TBC 2B 15-amp fuse directly through the BCM to these circuits.

Conditions for Running the DTC

The battery voltage must be between 9.0-16.0 volts.

Conditions for Setting the DTC

z

When the BCM receives a courtesy lamp illumination request signal and the courtesy lamp supply
voltage circuit is shorted to ground.

z

When the BCM is not receiving a courtesy lamp illumination request signal and the courtesy lamp supply
voltage circuit is open only to the first splice from the BCM or the circuit is shorted to voltage.

z

There is a loss of the instrument panel fuse block TBC 2B battery supply voltage to the BCM for 1
second.

Action Taken When the DTC Sets

The courtesy dome lamps will not operate or are always ON.

Conditions for Clearing the MIL/DTC

9

Replace the headlamp and panel dimmer switch. Refer to Headlamp
Switch Replacement .
Did you complete the replacement?

Go to

Step

11

-

10

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

IMPORTANT:

Perform the setup procedure for the BCM.

Go to

Step

11

-

11

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 Lighting Systems - Hummer H2