Hummer H2. Manual - part 1510

SCAN TOOL DATA DEFINITIONS 

The Engine Scan Tool Data Definitions contains a brief description of all engine related parameters available on 
the scan tool. The list is in alphabetical order. A given parameter may appear in any one of the data lists. In 
some cases, the parameter may appear more than once or in more than one data list in order to group certain 
related parameters together. 

4WD Signal  

This parameter displays the state of the transfer case based on the signal from the front axle indicator 
switch. The scan tool will display Enabled or Disabled. Enabled indicates the front axle is locked in four 
wheel drive and the front axle indicator switch is closed, supplying voltage to the controller on the axle 
switch signal circuit. Disabled indicates the transfer case is not in four wheel drive and the front axle 
indicator switch is open. 

4WD Low Signal  

This parameter displays the state of the transfer case based on the signal from the four wheel drive (4WD) 
low switch. The scan tool will display Enabled or Disabled. Enabled indicates the transfer case is in 4WD 
low gear and the 4WD low switch is closed, completing the low signal circuit. Disabled indicates the 
transfer case is not in 4WD low gear and the 4WD low switch is open. 

A/C Relay Command  

TP Desired Angle

Eng 1, Eng 2, EE, 

TAC, CC

0-100%

5.5%

TP Indicated Angle

All

0-100%

5.5%

TP Sensor 1

TAC

0-5.0 Volts

0.4-0.9 Volts

TP Sensor 1

TAC

0-100%

Varies near 0%

TP Sensor 2

TAC

5.0-0 Volts

Volts

TP Sensor 2

TAC

100-0%

Varies

TP Sensors 1 and 2

TAC

Agree/Disagree

Agree

TR Switch

CC, FT

Transmission Gear

Varies

Traction Control Signal

Eng 2, CC, TAC

Active/Inactive

Inactive

Vehicle Speed Sensor

All

km/h 

mph

0

VTD Auto Learn Timer

Eng 1

Active/Inactive

Inactive

VTD Fuel Disable

Eng 1

Active/Inactive

Inactive

VTD Fuel Disable Until 
Ign. Off

Eng 1

Yes/No

No

Warm-Ups w/o Emission 
Faults

Eng 2

0-255 Counts

Varies

Warm-Ups w/o Non-
Emission Faults

Eng 2

0-255 Counts

Varies

 

2004 Hummer H2 

2004 ENGINE PERFORMANCE Engine Controls (Diagnostic Information & Procedures) - 4.8L, 5.3L, and 6.0L - 

Hummer H2

  

This parameter displays the commanded state of the air conditioning (A/C) clutch relay control circuit. 
The scan tool will display ON or OFF. ON indicates the A/C clutch relay control circuit is being 
grounded by the control module, allowing voltage to the A/C compressor clutch. OFF indicates the A/C 
clutch relay is not being commanded on by the control module. 

A/C Request Signal  

This parameter displays the state of the air conditioning (A/C) request input to the control module from 
the heating, ventilation, and air conditioning (HVAC) controls. The scan tool will display Yes or No. Yes 
indicates the control module is receiving a request from the HVAC system to ground the A/C clutch relay 
control circuit, engaging the A/C compressor clutch. No indicates the control module is not receiving a 
request from the HVAC system to ground the A/C clutch relay control circuit. 

APP Average  

This parameter displays the average of the 3 accelerator pedal position (APP) sensors as calculated by the 
throttle actuator control (TAC) module. The APP average is a range of values indicating a low number 
when the accelerator pedal is not pressed to a high number when the accelerator pedal is fully pressed. 
This value is listed in counts. 

APP Indicated Angle  

This parameter displays the angle of the accelerator pedal as calculated by the control module using the 
signals from the accelerator pedal position sensors. The APP indicated angle is a range of values 
indicating a low percentage when the accelerator pedal is not pressed to a high percentage when the 
accelerator pedal is fully pressed. 

APP Sensor 1  

This parameter displays the voltage signal sent to the control module from accelerator pedal position 
(APP) sensor 1 of the APP sensor assembly. APP sensor 1 is a range of values indicating a low voltage 
when the accelerator pedal is not pressed to a high voltage when the accelerator pedal is fully pressed. 

APP Sensor 1  

This parameter displays the angle of the accelerator pedal position (APP) sensor 1 as calculated by the 
control module using the signal from the APP sensor 1. APP sensor 1 is a range of values indicating a low 
percentage when the accelerator pedal is not pressed to a high percentage when the accelerator pedal is 
fully pressed. 

APP Sensor 1 and 2  

This parameter displays the results of a control module test that compares the signals from the accelerator 
pedal position (APP) sensors 1 and 2. The scan tool will display Agree or Disagree. Agree indicates that 
APP sensor 1 and APP sensor 2 voltages correspond to the same accelerator pedal position. Disagree 
indicates that APP sensor 1 and APP sensor 2 voltages correspond to different accelerator pedal positions.

 

2004 Hummer H2 

2004 ENGINE PERFORMANCE Engine Controls (Diagnostic Information & Procedures) - 4.8L, 5.3L, and 6.0L - 

Hummer H2

  

APP Sensor 2  

This parameter displays the voltage signal sent to the control module from accelerator pedal position 
(APP) sensor 2 of the APP sensor assembly. APP sensor 2 is a range of values indicating a low voltage 
when the accelerator pedal is not pressed to a high voltage when the accelerator pedal is fully pressed. 

APP Sensor 2  

This parameter displays the angle of the accelerator pedal position (APP) sensor 2 as calculated by the 
control module using the signal from the APP sensor 2. APP sensor 2 is a range of values indicating a low 
percentage when the accelerator pedal is not pressed to a high percentage when the accelerator pedal is 
fully pressed. 

BARO  

This parameter displays the barometric pressure as calculated by the control module using the signal from 
the manifold absolute pressure (MAP) sensor measured when the ignition is turned on with the engine not 
running. The control module will update the barometric pressure during wide-open throttle (WOT) 
conditions. 

Clutch Pedal Switch  

This parameter displays the current state of the clutch pedal as determined by the control module. 

CMP Sensor - High To Low  

This parameter displays the number of times the signal voltage from the camshaft position (CMP) sensor 
changes from high to low. The scan tool will display these transitions as counts. 

CMP Sensor - Low To High  

This parameter displays the number of times the signal voltage from the camshaft position (CMP) sensor 
changes from low to high. The scan tool will display these transitions as counts. 

Coolant Level Switch  

This parameter displays the level of engine coolant as determined by the control module. The control 
module determines the level of the coolant using the signal from a switch used to monitor the engine 
coolant level. The scan tool will display low when the engine coolant level is low. The scan tool will 
display OK when the coolant level is correct. 

Cruise Control Active  

This parameter displays the status of the cruise control system as determined by the control module. The 
scan tool will display Yes when the cruise control system is in control of vehicle speed. The scan tool will 
display No when the cruise control system is not operating.

 

2004 Hummer H2 

2004 ENGINE PERFORMANCE Engine Controls (Diagnostic Information & Procedures) - 4.8L, 5.3L, and 6.0L - 

Hummer H2

  

Cruise Disengage 1-8 History  

The scan tool indicates the last 8 cruise control disengages in order, from 1 to 8. There are 20 possible 
causes for the cruise control to disengage. 

Cruise Inhibit Signal Command  

This parameter displays the commanded state of the cruise inhibit signal circuit. The scan tool will 
display On when the control module is inhibiting cruise control operation. The scan tool will display OFF 
when the control module is allowing cruise control operation. 

Cruise On/Off Switch  

This parameter displays the state of the On/Off switch input to the control module. The scan tool will 
display ON when the cruise switch is ON. 

Cruise Release Brake Pedal Switch  

This parameter displays the state of the Cruise Release Brake Pedal Switch as determined by the control 
module. The scan tool will display Released or Applied. Released indicates the brake pedal is not being 
pushed down, allowing the cruise control to be enabled. Applied indicates the brake switch is being 
applied, disabling cruise control operation. 

Cruise Resume/Accel Switch  

This parameter displays the state of the Resume/Accel switch input to the control module when the cruise 
control switch is in the on position and the Resume/Accel switch is activated, the scan tool displays On. 
When the Resume/Accel switch is released the scan tool displays OFF. 

Cruise Set/Coast Switch  

This parameter displays the state of the Set/Coast switch input to the control module from the cruise 
control system. When the cruise control switch is in the on position and the Set/Coast switch is activated, 
the scan tool displays On. When the Set/Coast switch is released the scan tool displays OFF. 

Current Gear  

This parameter displays the transmission gear commanded by the control module. The scan tool will 
display 1 when the control module has commanded first gear regardless of the gear selector position. The 
scan tool will display up to 6 depending upon which gear is commanded and what transmission is in the 
vehicle. The scan tool will display 9 if the transmission gear is not known. 

Cycles Of Misfire Data  

This parameter displays the number of cylinder firing events that were recorded as misfires as determined 
by the control module. 

 

2004 Hummer H2 

2004 ENGINE PERFORMANCE Engine Controls (Diagnostic Information & Procedures) - 4.8L, 5.3L, and 6.0L - 

Hummer H2