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Hummer H2. Manual - part 1683

connector containing the APP sensor circuits.

3. Turn ON the ignition, with the engine OFF.

4. Test the APP sensor 2 5-volt reference circuit

for a short to voltage with a DMM. Refer to
Circuit Testing and Wiring Repairs in
Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 13

Test the APP sensor 2 5-volt reference circuit for an
open or high resistance with a DMM. Refer to
Circuit Testing and Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

Go to Step 25

Go to Step 14

Test the APP sensor 2 5-volt reference circuit for a
short to ground with a DMM. Refer to Circuit
Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 25

Go to Step 15

Test for a short between the APP sensor 2 5-volt
reference circuit and all other TAC module circuits
with a DMM. Refer to Circuit Testing and Wiring
Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 25

Go to Step 23

Measure resistance with a DMM connected between
the APP sensor 2 low reference circuit and the APP
sensor 1 low reference circuit.
Does the DMM indicate resistance within the
specified values?

0-5

ohm

Go to Step 18

Go to Step 17

1. Turn OFF the ignition.

2. Disconnect the TAC module harness

connector containing the APP sensor circuits.

3. Test the APP sensor 2 low reference circuit for

an open or high resistance with a DMM. Refer
to Circuit Testing and Wiring Repairs in
Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 23

1. Connect a fused jumper between the APP

sensor 2 signal circuit and the APP sensor 2
low reference circuit at the APP sensor harness
connector.

2. Observe the APP sensor 2 voltage parameter

with a scan tool.

Does the scan tool indicate APP sensor 2 voltage is

0 V

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0507 (TAC) To DTC U0107) - 4.8L, 5.3L, and 6.0L -

Hummer H2

at the specified value?

Go to Step 19

Go to Step 23

1. Observe the APP sensor 1, the APP sensor 3,

and the TP sensor 2 voltage parameters with a
scan tool.

2. Connect a fused jumper between the APP

sensor 2 signal circuit and the APP sensor 2
low reference circuit at the APP sensor harness
connector.

Did the scan tool indicate a change in voltage in any
of the parameters observed during the above test?

Go to Step 20

Go to Step 21

1. Turn OFF the ignition.

2. Disconnect the TAC module harness

connectors.

3. Test for a short between the APP sensor 2

signal circuit and all other TAC module
circuits with a DMM. Refer to Circuit
Testing and Wiring Repairs in Wiring
Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 23

Inspect for poor connections at the harness connector
of the APP sensor. Refer to Testing for
Intermittent Conditions and Poor Connections
and Repairing Connector Terminals in Wiring
Systems.
Did you find and correct the condition?

Go to Step 25

Go to Step 22

Replace the APP sensor assembly. Refer to
Accelerator Pedal Position (APP) Sensor
Replacement .
Did you complete the replacement?

Go to Step 25

Inspect for poor connections at the harness connector
of the TAC module. Refer to Testing for
Intermittent Conditions and Poor Connections
and Repairing Connector Terminals in Wiring
Systems.
Did you find and correct the condition?

Go to Step 25

Go to Step 24

Replace the TAC module. Refer to Throttle
Actuator Control (TAC) Module Replacement .
Did you complete the replacement?

Go to Step 25

1. Clear the DTCs with a scan tool.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0507 (TAC) To DTC U0107) - 4.8L, 5.3L, and 6.0L -

Hummer H2

DTC P2135

Circuit Description

The throttle position (TP) sensors 1 and 2 are potentiometer type sensors, each with the following three circuits:

A 5-volt reference circuit

A low reference circuit

A signal circuit

The TP sensors are used to determine the throttle plate angle for various engine management systems. The
control module provides each TP sensor a 5-volt reference circuit and a low reference circuit. The TP sensors
then provide the control module with signal voltage proportional to throttle plate movement. Both TP sensor
signal voltages are low at closed throttle and increase as the throttle opens. When the control module detects
that TP sensor 1 signal and the TP sensor 2 signals disagree, or signal voltages are outside the predetermined
range, this DTC sets.

Conditions for Running the DTC

DTCs P2108 or U0107 are not set.

The ignition switch is in the Crank or Run position.

The ignition voltage is more than 5.23 volts.

Conditions for Setting the DTC

The TP sensor 2 disagrees with the TP sensor 1 by more than 7.5 percent.

The above condition is present for more than 1 second.

Action Taken When the DTC Sets

The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

The control module records the operating conditions at the time the diagnostic fails. The control module
stores this information in the Freeze Frame and/or the Failure Records.

4. Operate the vehicle within the Conditions for

Running the DTC. You may also operate the
vehicle within the conditions that you
observed from the Freeze Frame/Failure
Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 26

Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?

Go to

Diagnostic

Trouble Code

(DTC) List

System OK

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0507 (TAC) To DTC U0107) - 4.8L, 5.3L, and 6.0L -

Hummer H2

The control module commands the TAC system to operate in the Reduced Engine Power mode.

A message center or an indicator displays Reduced Engine Power.

Under certain conditions the control module commands the engine OFF.

Conditions for Clearing the MIL/DTC

The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles
that the diagnostic runs and does not fail.

A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other
emission related diagnostic.

Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

Inspect the throttle actuator control (TAC) module connectors for signs of water intrusion. If water
intrusion occurs, multiple DTCs may set without any circuit or component conditions found during
diagnostic testing.

When the TAC module detects a condition within the TAC system, more than one TAC system related
DTC may set. This is due to the many redundant tests run continuously on this system. Locating and
repairing one individual condition may correct more than one DTC. Disconnecting components during
testing may set additional DTCs. Remember this if you review the stored information in Capture Info.

If this DTC is determined to be intermittent, refer to Intermittent Conditions .

Test Description

The number below refers to the step number on the diagnostic table.

21: When the TAC module detects a condition within the TAC system, more than one TAC system
related DTC may set. This is due to the many redundant tests run continuously on this system. Locating
and repairing one individual condition may correct more than one DTC. Disconnecting components
during testing may set additional DTCs. Remember this if you review the stored information in Capture
Info.

DTC P2135

Step

Action

Yes

Schematic Reference:Engine Controls Schematics
Connector End View Reference:Engine Controls Connector End Views or Powertrain Control
Module (PCM) Connector End Views

Did you perform the Diagnostic System Check - Engine
Controls?

Go to Step 2

Go to Diagnostic

System Check -

Engine Controls

Is DTC U0107 set?

Go to Diagnostic

Trouble Code

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0507 (TAC) To DTC U0107) - 4.8L, 5.3L, and 6.0L -

Hummer H2

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