Hummer H2. Manual — part 198

RETAINED ACCESSORY POWER (RAP) INOPERATIVE

Retained Accessory Power (RAP) Inoperative

5

circuit. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?

Go to

Step 12

-

6

1. Open the driver door.

2. Connect a test lamp across the relay coil circuits of the

sunroof relay.

3. Turn ON the ignition, with the engine OFF.

4. Turn OFF the ignition.

Does the test lamp illuminate?

Go to

Step 7

Go to Step 8

7

Test the RAP supply voltage circuit for a short to B+.
Turn the ignition ON, with the engine OFF, when testing for a
short to voltage. Refer to Circuit Testing and to Wiring
Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step 12

Go to Step 10

8

Inspect for poor connections at the sunroof relay. Refer to
Testing for Intermittent Conditions and Poor Connections
and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step 12

Go to Step 9

9

Replace the sunroof relay.
Did you complete the replacement?

Go to

Step 12

-

10

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 12

Go to Step 11

11

Replace the BCM. Refer to Control Module References in
Body Control System.Did you complete the procedure?

IMPORTANT:

Perform the module setup procedure if required.

Go to

Step 12

-

12

Operate the system in order to verify the repair.
Did you correct the condition?

System

OK

Go to Step 2

Step

Action

Yes

No

Schematic Reference:Retained Accessory Power (RAP) Schematics
Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check -
Retained Accessory Power?

Go to Step 2

Go to Diagnostic

System Check -

Retained Accessory

Power

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Retained Accessory Power - Hummer H2

2

1. Close all of the doors.

2. Turn ON the ignition, with the engine

OFF.

3. Turn OFF the ignition.

Do all the retained accessory power functions
operate during the RAP time?

Go to Testing for

Intermittent Conditions

and Poor Connections in

Wiring Systems

Go to Step 3

3

Does only sunroof exhibit this symptom?

Go to Step 5

Go to Step 4

4

1. Install a scan tool. Select diagnostic circuit

check and then class 2 power mode.

2. Close all of the doors.

3. Turn ON the ignition, with the engine

OFF.

4. Wait 5 seconds then turn the ignition OFF.

5. Wait the time-out for RAP.

Did the scan tool display the RAP power mode
then time-out, and display Off-Awake power
mode?

Go to Step 5

Go to Step 15

5

1. Turn OFF the ignition.

2. Disconnect the sunroof relay.

3. Turn ON the ignition, with the engine

OFF.

4. With a test lamp that is connected to a

good ground, probe the battery positive
voltage circuit of the sunroof relay.

Does the test lamp illuminate?

Go to Step 6

Go to Step 12

6

1. Connect a test lamp between the relay coil

circuits of the sunroof relay.

2. Turn the ignition ON, with the engine

OFF.

Does the test lamp illuminate?

Go to Step 9

Go to Step 7

7

Test the RAP supply voltage circuit for a short to
ground or an open.
Turn the ignition ON, with the engine OFF,
when testing for a short to voltage. Refer to
Circuit Testing and to Wiring Repairs in
Wiring Systems.
Did you find and correct the condition?

Go to Step 17

Go to Step 8

8

Test the sunroof relay ground circuit for an open.

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Retained Accessory Power - Hummer H2

DESCRIPTION AND OPERATION

Did you find and correct the condition?

Go to Step 17

Go to Step 15

9

1. Connect a fused wire jumper across the

relay switched circuits of the sunroof
relay.

2. Turn the ignition ON, with the engine

OFF.

3. Attempt to operate the sunroof.

Does the sunroof operate normally?

Go to Step 11

Go to Step 10

10

Repair the sunroof relay switch output circuit.
Refer to Wiring Repairs in Wiring Systems.
Did you complete the replacement?

Go to Step 17

-

11

Inspect for poor connections at the sunroof 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 17

Go to Step 14

12

Test the sunroof supply voltage circuit for a short
to ground.
Did you find and correct the condition?

Go to Step 17

Go to Step 13

13

Repair the battery positive voltage circuit of the
sunroof relay. Refer to Wiring Repairs in
Wiring Systems.
Did you complete the repair?

Go to Step 17

-

14

Replace the sunroof relay.
Did you complete the replacement?

Go to Step 17

-

15

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 17

Go to Step 16

16

Replace the BCM. Refer to Control Module
References in Body Control System.Did you
complete the procedure?

IMPORTANT:

Perform the module setup procedure if
required.

Go to Step 17

-

17

Operate the system in order to verify the repair.
Did you correct the condition?

System OK

Go to Step 3

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Retained Accessory Power - Hummer H2

RETAINED ACCESSORY POWER (RAP) DESCRIPTION AND OPERATION

Serial Data Control of Retained Accessory Power (RAP)

The class 2 modules receive the power mode message from the body control module (BCM) over the serial data
circuits, indicating when the RAP power mode is current. The BCM monitors the ignition switch position,
battery condition and passenger compartment doors status to determine whether RAP should be initiated. The
modules then support the operation of the systems under their control as required by their RAP power mode
operation.

RAP will end when one of the following conditions is met:

z

The BCM receives an input or class 2 message indicating the opening of any compartment door.

z

The BCM internal timer for the RAP expires after approximately 10 minutes.

z

The BCM detects a decrease in battery capacity below a prescribed limit.

The BCM then sends a serial data power mode message Off-Awake ending the RAP function.

The class 2 RAP functions are:

z

The power windows

z

The radio

Relay Control of Retained Accessory Power (RAP)

The sunroof is controlled through the sunroof relay. The body control module (BCM) keeps the sunroof relay
energized during all power modes, except Off-Awake. The sunroof relay provides power for sunroof operation.

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Retained Accessory Power - Hummer H2