Hummer H2. Manual - part 1612

bank is running lean. The scan tool will display a high voltage reading when that cylinder bank is running 
rich. 

HO2S Bank 1 Sensor 2  

This parameter displays the voltage from the signal produced by the heated oxygen sensor used to 
monitor catalyst efficiency for cylinder bank 1. The scan tool will display a low voltage reading when that 
cylinder bank is running lean. The scan tool will display a high voltage reading when that cylinder bank is 
running rich. 

HO2S Bank 2 Sensor 1  

This parameter displays the voltage from the signal produced by the heated oxygen sensor used to 
monitor fuel trim for cylinder bank 2. The scan tool will display a low voltage reading when that cylinder 
bank is running lean. The scan tool will display a high voltage reading when that cylinder bank is running 
rich. 

HO2S Bank 2 Sensor 2  

This parameter displays the voltage from the signal produced by the heated oxygen sensor used to 
catalyst efficiency for cylinder bank 2. The scan tool will display a low voltage reading when that 
cylinder bank is running lean. The scan tool will display a high voltage reading when that cylinder bank is 
running rich. 

HO2S Heater Bank 1 Sensor 1  

This parameter displays the current through the control module when the bank 1 sensor 1 HO2S heater is 
commanded ON by the control module. HO2S Heater Bank 1 Sensor 1 is a range of values indicating a 
low current when the heater circuit resistance is high to a high current when the heater circuit resistance is 
low. 

HO2S Heater Bank 1 Sensor 2  

This parameter displays the current through the control module when the bank 1 sensor 2 HO2S heater is 
commanded ON by the control module. HO2S Heater Bank 1 Sensor 2 is a range of values indicating a 
low current when the heater circuit resistance is high to a high current when the heater circuit resistance is 
low. 

HO2S Heater Bank 2 Sensor 1  

This parameter displays the current through the control module when the bank 2 sensor 1 HO2S heater is 
commanded ON by the control module. HO2S Heater Bank 2 Sensor 1 is a range of values indicating a 
low current when the heater circuit resistance is high to a high current when the heater circuit resistance is 
low. 

HO2S Heater Bank 2 Sensor 2  

 

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This parameter displays the current through the control module when the bank 2 sensor 2 HO2S heater is 
commanded ON by the control module. HO2S Heater Bank 2 Sensor 2 is a range of values indicating a 
low current when the heater circuit resistance is high to a high current when the heater circuit resistance is 
low. 

IAT Sensor  

This parameter displays the temperature of the intake air calculated by the control module based on the 
input from the intake air temperature (IAT). The scan tool will display a low value for a low intake air 
temperature, and a high value for a high intake air temperature. 

Ignition 1 Signal  

This parameter displays the voltage measured at the ignition 1 circuit of the control module. Voltage is 
applied to the control module when the ignition switch is in the ignition 1 position. 

Injector PWM Bank 1 Average  

The scan tool displays milliseconds. This parameter is the average time the control module turns on each 
fuel injector on that bank. The scan tool will display a higher value with a longer pulse width, or a lower 
value with a shorter pulse width. 

Injector PWM Bank 2 Average  

The scan tool displays milliseconds. This parameter is the average time the control module turns on each 
fuel injector on that bank. The scan tool will display a higher value with a longer pulse width, or a lower 
value with a shorter pulse width. 

Knock Retard  

The scan tool displays in degrees. This parameter indicates the amount of timing retard commanded by 
the control module. The scan tool will display a lower value if no knock is detected, and a higher value as 
more knock is detected and the control module retards the ignition timing. 

Long Term FT Avg. Bn1  

The scan tool displays %. This parameter is the average long term fuel trim for this bank as calculated by 
the control module. The scan tool will display a value of more than 0 percent indicating that time is being 
added to the injector pulse width, increasing the amount of fuel to this bank of the engine. The scan tool 
will display a value of less than 0 indicating time is being subtracted from the injector pulse width, 
reducing the amount of fuel to this bank of the engine. A value of 0 percent indicates no compensation is 
required to operate the engine at the desired air/fuel ratio. 

Long Term FT Avg. Bn2  

The scan tool displays %. This parameter is the average long term fuel trim for this bank as calculated by 
the control module. The scan tool will display a value of more than 0 percent indicating that time is being 

 

2004 Hummer H2 

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

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added to the injector pulse width, increasing the amount of fuel to this bank of the engine. The scan tool 
will display a value of less than 0 indicating time is being subtracted from the injector pulse width, 
reducing the amount of fuel to this bank of the engine. A value of 0 percent indicates no compensation is 
required to operate the engine at the desired air/fuel ratio. 

Long Term FT Bank 1  

The scan tool displays %. This parameter is the long term fuel trim for this bank as calculated by the 
control module. The scan tool will display a value of more than 0 percent indicating that time is being 
added to the injector pulse width, increasing the amount of fuel to this bank of the engine. The scan tool 
will display a value of less than 0 indicating time is being subtracted from the injector pulse width, 
reducing the amount of fuel to this bank of the engine. A value of 0 percent indicates no compensation is 
required to operate the engine at the desired air/fuel ratio. 

Long Term FT Bank 2  

The scan tool displays %. This parameter is the long term fuel trim for this bank as calculated by the 
control module. The scan tool will display a value of more than 0 percent indicating that time is being 
added to the injector pulse width, increasing the amount of fuel to this bank of the engine. The scan tool 
will display a value of less than 0 indicating time is being subtracted from the injector pulse width, 
reducing the amount of fuel to this bank of the engine. A value of 0 percent indicates no compensation is 
required to operate the engine at the desired air/fuel ratio. 

Loop Status  

The scan tool displays Open or Closed. The scan tool displays Closed Loop if the control module is 
controlling the fuel delivery according to the heated oxygen sensor (HO2S) voltages. The scan tool 
displays open loop if the control module is not adjusting for HO2S inputs. In open loop the control 
module bases fuel deliver on throttle position, engine coolant temperature, and mass airflow sensor 
inputs. 

Low Oil Lamp Command  

This parameter displays the commanded state of the low oil lamp control circuit by the control module. 
The scan tool will display ON if the lamp is commanded ON by the control module. The scan tool will 
display OFF if the lamp is not being commanded by the control module. 

MAF Sensor  

The scan tool displays g/s. This parameter indicates the airflow into the engine as calculated by the 
control module based on mass airflow (MAF) sensor inputs. The scan tool will display a high value at 
higher engine speeds, and a low value at idle. 

MAF Sensor  

The scan tool displays in Hz. This parameter indicates the frequency signal sent from the MAF sensor to 
the control module. the scan tool will display a high value indicates a higher engine speed. The scan tool 

 

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will display a low value at idle. 

MAP Sensor  

The scan tool displays kPa. This parameter displays the pressure inside of the intake manifold as 
calculated by the control module based on the input from the MAP sensor. The scan tool will display a 
high value at wide open throttle (WOT). The scan tool will display a low value at idle speed. 

MAP Sensor  

This parameter displays the voltage signal from the MAP sensor to the control module. The scan tool will 
display a high value at wide open throttle (WOT). The scan tool will display a low value at idle speed. 

MIL Command  

This parameter displays the commanded state of the malfunction indicator lamp (MIL) control circuit. 
The malfunction indicator lamp should be ON when the scan tool indicates the MIL Command is ON. 
The malfunction indicator lamp should be OFF when the scan tool indicates the MIL Command is OFF. 
The control module will command the MIL ON when the ignition is ON with the engine OFF in order to 
perform a bulb check. 

Mileage Since DTC Cleared  

The scan tool displays km or miles. This parameter indicates the mileage accumulated since an emission 
diagnostic trouble code cleared. 

Mileage Since First Failure  

The scan tool will display in km or miles. This parameter indicates the difference in mileage between 
when the DTC first set and the current vehicle mileage as calculated by the control module. 

Mileage Since Last Failure  

The scan tool will display in km or miles. This parameter indicates the difference in mileage between 
when the DTC last set and the current vehicle mileage as calculated by the control module. 

Misfire Counter Status  

The misfire counter shows the relative number of failed misfire tests since the misfire DTC P0300 
became active. 

Misfire Current Cyl. #1 - #8  

The scan tool will display in counts. This parameter indicates the number of cylinder firing events 
detected as possible misfires on each cylinder during the last 200 crankshaft revolutions as calculated by 
the control module. The scan tool will display a low number for a low number of cylinder misfire events. 
The scan tool will display a high number for a high number of cylinder misfire events. 

 

2004 Hummer H2 

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

Hummer H2