Hummer H2. Manual — part 1512

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 -

Hummer H2

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

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Hummer H2