Hummer H2. Manual — part 2651

SCAN TOOL OUTPUT CONTROLS

Scan Tool Output Controls

SCAN TOOL DATA LIST

Does the scan tool display any
DTCs?

Go to Step 8

Go to Symptoms - Transfer

Case

8

Does the scan tool display any
DTCs which begin with a "U"?

Go to Scan Tool Does Not

Communicate with Class 2

Device in Data Link

Communications

Go to Step 9

9

Does the scan tool display DTC
P0502 or P0503?

Go to Applicable Powertrain

OBD Diagnostic System Check

Go to Diagnostic Trouble

Code (DTC) List

Scan Tool

Output Control

Additional

Menu

Selections

Description

Refer to the scan tool manual for complete scan tool operating instructions.

4WD High

Indicator Light

-

This function allows the technician to command the 4WD high
indicator light, within the transfer case shift control switch, on or off.

4WD High Lock

Indicator Light

-

This function allows the technician to command the 4WD high lock
indicator light, within the transfer case shift control switch, on or off.

4WD Low Lock

Indicator Light

-

This function allows the technician to command the 4WD low lock
indicator light, within the transfer case shift control switch, on or off.

Differential

Lock Indicator

Light

-

This function allows the technician to command the differential
indicator light, within the transfer case shift control switch, on or off.

Motor A Driver

- High

-

This function allows the technician to request the high side driver for
the motor control A circuit, thus allowing the technician to test the
circuit and the transfer case shift control module for their ability to
provide battery voltage to the motor.

Motor A Driver

- Low

-

This function allows the technician to request the low side driver for
the motor control A circuit, thus allowing the technician to test the
circuit and the transfer case shift control module for their ability to
provide a ground path for the motor.

Motor B Driver -

High

-

This function allows the technician to request the high side driver for
the motor control B circuit, thus allowing the technician to test the
circuit and the transfer case shift control module for their ability to
provide battery voltage to the motor.

Motor B Driver -

Low

-

This function allows the technician to request the low side driver for
the motor control B circuit, thus allowing the technician to test the
circuit and the transfer case shift control module for their ability to
provide a ground path for the motor.

Neutral Indicator

Light

-

This function allows the technician to command the neutral indicator
light, within the transfer case shift control switch, on or off.

2004 Hummer H2

2004 DRIVELINE/AXLE Transfer Case - BW 4484 - Hummer H2

Scan Tool Data List

Scan Tool Parameter

Data List

Units Displayed

Typical Data

Value

Engine is at Idle, Upper Radiator Hose is Hot, Closed Throttle, Gear is in Park or Neutral, and

Accessories are OFF.

4WD High Indicator Light

Transfer Case

Data

On/Off

Off

4WD High Lock Indicator Light

Transfer Case

Data

On/Off

Off

4WD Low Active

Transfer Case

Data

Yes/No

No

4WD Low Lock Indicator Light

Transfer Case

Data

On/Off

Off

ATC Application

Transfer Case

Data

Number

Number

Encoder Circuit A

Transfer Case

Data

On/Off

On

Encoder Circuit B

Transfer Case

Data

On/Off

On

Encoder Circuit C

Transfer Case

Data

On/Off

On

Encoder Circuit P

Transfer Case

Data

On/Off

On

Encoder Gear Position

Transfer Case

Data

4WD High/4WD

Low/AWD

4WD High

Encoder Supply Voltage

Transfer Case

Data

Volts

2.55

Ign. Cycles Since Last Current
DTC

Transfer Case

Data

Count

Varies

Mode Switch Return Voltage

Transfer Case

Data

Volts

0-5 V

Mode Switch Selected

Transfer Case

Data

Transfer Case Mode

Inactive

Motor A High Side Driver Status

Transfer Case

Data

On/Off

NO

Motor A Low Side Driver Status

Transfer Case

Data

On/Off

NO

Motor B High Side Driver Status

Transfer Case

Data

On/Off

NO

Motor B Low Side Driver Status

Transfer Case

Data

On/Off

NO

Neutral Indicator Light

Transfer Case

Data

On/Off

Off

Transfer Case

2004 Hummer H2

2004 DRIVELINE/AXLE Transfer Case - BW 4484 - Hummer H2

SCAN TOOL DATA DEFINITIONS

4WD High Indicator Light

The scan tool displays On or Off. This parameter indicates On when the transfer case shift control module
commands the rear 4WD high indicator light On.

4WD High Lock Indicator Light

The scan tool displays On or Off. This parameter indicates On when the transfer case shift control module
commands the rear 4WD high lock indicator On.

4WD Low Active

The scan tool displays Yes or No. This parameter indicates Yes when the transfer case is currently in the
4WD low lock mode.

4WD Low Lock Indicator Light

The scan tool displays On or Off. This parameter indicates On when the transfer case shift control module
commands the rear 4WD low lock indicator light On.

ATC Application

The scan tool displays a numeric value. This parameter indicates the model number assigned to the
transfer case.

Encoder Circuits A, B, C, and P

The scan tool displays On or Off. If a high voltage is detected then the circuit is Off. If the encoder motor
grounds the circuit and pulls the voltage low then the circuit is On. The encoder circuits allow the transfer
case shift control module to determine what position the transfer case is in.

Encoder Gear Position

The scan tool displays the mode the transfer case is currently in.

Encoder Supply Voltage

Rear Axle Lock

Data

On/Off

Off

Rear Axle Lock Indicator Lamp

Transfer Case

Data

On/Off

Off

Rear Axle Lock Request

Transfer Case

Data

On/Off

Off

Software ID

Transfer Case

Data

Part Number

Part Number

2004 Hummer H2

2004 DRIVELINE/AXLE Transfer Case - BW 4484 - Hummer H2

The scan tool displays a range from 0-25 volts. This parameter indicates the voltage supplied to the
encoder motor.

GM Part Number

The scan tool displays a numeric value. This parameter indicates the GM part number assigned to the
module package (module, software, and calibrations).

Ign. Cycles Since Last Current DTC

The scan tool displays a numeric value. This parameter indicates how many ignition cycles have occurred
since last current DTC was set.

Mode Switch Return Voltage

The scan tool displays a range of 0-5 volts. This parameter indicates the return voltage from the transfer
case shift control switch.

Mode Switch Selected

The scan tool displays the current mode selected. This parameter indicates the transfer case shift control
switch button currently depressed by the driver.

Motor A High Side Driver

The scan tool displays On or Off. This parameter indicates On when battery voltage is applied to the
Motor A circuit.

Motor A Low Side Driver

The scan tool displays On or Off. This parameter indicates On when ground is applied to the Motor A
circuit.

Motor B High Side Driver

The scan tool displays On or Off. This parameter indicates On when battery voltage is applied to the
Motor B circuit.

Motor B Low side Driver

The scan tool displays On or Off. This parameter indicates On when ground is applied to the Motor B
circuit.

Neutral Indicator Light

The scan tool displays On or Off. This parameter indicates On when the transfer case shift control module

2004 Hummer H2

2004 DRIVELINE/AXLE Transfer Case - BW 4484 - Hummer H2