Hummer H2. Manual — part 1513

Misfire History Cyl. #1 - #8

The scan tool displays in counts. This parameter displays the total level of cylinder misfires that have
been calculated for each cylinder by the control module. This parameter will not update or show activity
until a misfire DTC has become active. The misfire history counters will update every 200 cylinder firing
events.

Not Run Counter

The scan tool displays the number of times a DTC diagnostic has not reached the predetermined criteria
in order to run since the first DTC run failure.

Pass Counter

The scan tool displays the number of times a DTC has run and passed.

PCM Reset

The scan tool displays Yes or No. This parameter indicates when the internal PCM resets. The scan tool
displays YES when an internal PCM reset occurred. The scan tool displays NO under the normal
operating conditions.

PCM/VCM in VTD Fail Enable

The scan tool displays Yes or No. The scan tool displays Yes if the body control module (BCM) and the
control module lose communications with each other after the BCM sends the correct password. The scan
tool displays No if the BCM is communicating the correct password to the PCM.

Power Enrichment

Scan tool displays ACTIVE or INACTIVE. ACTIVE displayed indicates that the control module has
detected conditions appropriate to operate in Power Enrichment mode. The control module commands
Power Enrichment mode when a large increase in throttle position and load is detected. While in Power
Enrichment, the control module will increase the amount of fuel delivered by entering Open Loop and
increasing the injector pulse width.

Reduced Engine Power

The scan tool displays Active or Inactive. The scan tool displays Active when the control module receives
a signal from the TAC module that a throttle actuator control system fault is occurring. The scan tool
displays inactive when the engine is operating normally.

Short Term FT Avg. Bn1

The scan tool displays %. This parameter indicates the average short term fuel trim for this bank. The
scan tool will display a value more than 0 if the time is being added to the injector pulse width, increasing
the amount of fuel to that bank of the engine to compensate for a lean condition sensed by the oxygen

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

Hummer H2

sensors on that bank. The scan tool will display a value less than 0 if time is being subtracted from the
injector pulse width, reducing the amount of fuel to the engine to compensate for a rich condition sensed
by the oxygen sensors on that bank. A value of 0 percent indicates no compensation is required to operate
the engine at the desired air/fuel ratio.

Short Term FT Avg. Bn2

The scan tool displays %. This parameter indicates the average short term fuel trim for this bank. The
scan tool will display a value more than 0 if the time is being added to the injector pulse width, increasing
the amount of fuel to that bank of the engine to compensate for a lean condition sensed by the oxygen
sensors on that bank. The scan tool will display a value less than 0 if time is being subtracted from the
injector pulse width, reducing the amount of fuel to the engine to compensate for a rich condition sensed
by the oxygen sensors on that bank. A value of 0 percent indicates no compensation is required to operate
the engine at the desired air/fuel ratio.

Short Term FT Bank 1

The scan tool displays %. This parameter indicates the current short term fuel trim for this bank. The scan
tool will display a value more than 0 if the time is being added to the injector pulse width, increasing the
amount of fuel to that bank of the engine to compensate for a lean condition sensed by the oxygen sensors
on that bank. The scan tool will display a value less than 0 if time is being subtracted from the injector
pulse width, reducing the amount of fuel to the engine to compensate for a rich condition sensed by the
oxygen sensors on that bank. A value of 0 percent indicates no compensation is required to operate the
engine at the desired air/fuel ratio.

Short Term FT Bank 2

The scan tool displays %. This parameter indicates the current short term fuel trim for this bank. The scan
tool will display a value more than 0 if the time is being added to the injector pulse width, increasing the
amount of fuel to that bank of the engine to compensate for a lean condition sensed by the oxygen sensors
on that bank. The scan tool will display a value less than 0 if time is being subtracted from the injector
pulse width, reducing the amount of fuel to the engine to compensate for a rich condition sensed by the
oxygen sensors on that bank. A value of 0 percent indicates no compensation is required to operate the
engine at the desired air/fuel ratio.

Spark

This parameter is the desired spark advance calculated by the control module based on many sensor
inputs. The scan tool will display a lower value at idle speed, and a higher value under heavy acceleration
and load conditions.

Start Up ECT

This parameter indicates the engine coolant temperature at startup, as calculated by the control module
based on the input from the engine coolant temperature sensor. The scan tool will display a higher value
at higher engine startup temperatures, and a lower value at lower startup temperatures.

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

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Stop Lamp Pedal Switch

This parameter displays the state of the brake pedal as determined by the control module based on an
input from the stop lamp pedal switch. This switch turns ON the stop lamps when the brake pedal is
pressed. The scan tool will display Applied when the brake pedal is pressed.

TAC/PCM Communication Signal

This parameter indicates the status of the communication between the TAC module and the control
module. The scan tool will display OK if the circuits are operating normally. The scan tool will display
Fault if there is an interrupt in the communication.

TCC Enable Solenoid Command

This parameter displays the commanded state of the torque converter clutch (TCC) solenoid control
circuit. The scan tool will display ON or OFF. ON indicates the TCC solenoid control circuit is being
grounded by the control module, operating the torque converter. OFF indicates the TCC solenoid is not
being commanded ON by the control module.

TCC PWM Solenoid Command

This parameter indicates the commanded state of the TCC PWM Solenoid by the control module. The
scan tool displays ON or OFF. The scan tool displays ON when the commanded state of the solenoid is
ON. The scan tool displays OFF when the solenoid is OFF.

TFP Switch

The scan tool displays Park/Neutral, Reverse, Drive, or Invalid. This display indicates the decoded status
of the two A/B inputs from the automatic transmission fluid pressure manual valve position switch.

Torque Delivered Signal

The scan tool displays ft-lbs or N.m. This parameter represents the pulse width modulation (PWM) signal
which indicates the percent of available torque the engine is delivering to the drive wheels. The electronic
brake/traction control module (EBCM) monitors the Traction Control Torque signal to ensure that the
powertrain control module (PCM) is responding properly to the Traction Control Desired Torque signal.

Torque Request Signal

The scan tool displays ft-lbs or N.m. Represents the pulse width modulation (PWM) signal from the
electronic brake and traction control module. The electronic brake/traction control module (EBCM)
reduces the traction control desired torque signal pulse width when a drive wheel slippage situation is
detected. The powertrain control module (PCM) monitors the traction control desired torque signal and
reduces drive wheel slippage as necessary by retarding spark timing, decreasing boost solenoid PWM, or
increasing air/fuel ratio. The PCM can also turn OFF up to three fuel injectors if the traction control
desired torque signal indicates a large enough amount of drive wheel slippage.

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

Hummer H2

TP Desired Angle

This parameter indicates the TP angle commanded by the control module. The scan tool will display a
low value at idle, and a high value at wide open throttle (WOT).

TP Indicated Angle

This parameter displays the angle of the throttle position (TP) in percent. This information is calculated
by the control module using the signals from the throttle position sensors. The scan tool will display a low
percentage when the throttle plates are closed. The scan tool will display a high percentage when the
throttle plates are fully open.

TP Sensor 1

This parameter displays the voltage signal sent to the control module from the sensor used to monitor the
position of the throttle plates. This parameter is for sensor 1 of the throttle position (TP) sensor assembly.
The scan tool will display a low voltage when the throttle plates are at rest. The scan tool will display a
high voltage when the throttle plates are fully open.

TP Sensor 1

This parameter displays the angle of the throttle position (TP) sensor 1 in percent. This information is
calculated by the control module using the signal from the throttle position sensor 1. The scan tool will
display a low percentage when the throttle plates are closed. The scan tool will display a high percentage
when the throttle plates are fully open.

TP Sensor 2

This parameter displays the voltage signal sent to the control module from the sensor used to monitor the
position of the throttle plates. This parameter is for sensor 2 of the throttle position (TP) sensor assembly.
The scan tool will display a high voltage when the throttle plates are at rest. The scan tool will display a
low voltage when the throttle plates are fully open.

TP Sensor 2

This parameter displays the angle of the throttle position (TP) sensor 2 in percent. This information is
calculated by the control module using the signal from the throttle position sensor 2. The scan tool will
display a low percentage when the throttle plates are closed. The scan tool will display a high percentage
when the throttle plates are fully open.

TP Sensors 1 and 2

This parameter displays the results of a control module test that compares signals from the throttle
position (TP) sensors 1 and 2. The scan tool will display Agree when the signal from TP sensor 1
corresponds with the signal from TP sensor 2. The scan tool will display Disagree when the signal from
TP sensor 1 conflicts with the signal from TP sensor 2.

2004 Hummer H2

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

Hummer H2