Hummer H2. Manual - part 1577

The TAC system is not in the battery saver mode.

Conditions for Setting the DTC

The TAC module detects that the predicted and the actual throttle positions are not within a calibrated
range of each other.

The PCM and the TAC cannot determine the throttle position.

Both of the TP sensors are invalid.

All of the above conditions are met 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.

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 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.

Verify that the starting and charging systems are operating properly. Low system voltage can cause this
DTC to set.

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 an 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.

For an intermittent, refer to Intermittent Conditions .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

2004 Hummer H2

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

Hummer H2

7: If the TP indicated angle does not follow the movement of the throttle blade and no TP sensor DTCs
are set, there is a mechanical condition with the throttle shaft or the TP sensor.

18: Locating and repairing an individual condition may correct more than one DTC.

DTC P1516

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 DTC

U0107

Go to Step 3

Is DTC P2135 set?

Go to DTC

P2135

Go to Step 4

1. Turn OFF the ignition for 15 seconds.

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

3. Observe the throttle position (TP) sensor 1 and TP

sensor 2 angle parameters with a scan tool.

4. Slowly depress the accelerator pedal to wide open

throttle (WOT) and slowly return it to the released
position.

Does the scan tool indicate both angle parameters increasing
as the pedal is depressed to WOT and decreasing as the
pedal is released?

IMPORTANT:

Low system voltage may cause this DTC to set. Clear
DTCs if low system voltage has been experienced.

Go to Diagnostic

Aids

Go to Step 5

1. Turn OFF the ignition.

2. Disconnect the throttle actuator motor harness

connector.

3. Remove the air inlet duct from the throttle body.

4. Inspect the throttle body and throttle plate for the

following conditions which may cause the throttle
plate to bind:

Debris - If debris is found, clean the throttle
body and repair the source of contamination.

Damage or evidence of tampering-If the throttle
body and/or throttle plate is damaged, replace
the throttle body. Refer to Throttle Body

2004 Hummer H2

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

Hummer H2

Assembly Replacement .

Did you find and correct the condition?

Go to Step 17

Go to Step 6

With your hand, slowly open the throttle plate to WOT and
back to the closed position several times.
Does the throttle plate move smoothly without binding in
both directions?

Go to Step 7

Go to Step 14

1. Turn OFF the ignition.

2. Disconnect the throttle body harness connector.

3. Connect the jumper wires between the TP sensor

terminals of the throttle body harness connector and
the corresponding TP sensor terminals of the throttle
body.

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

5. Open the throttle blade to WOT, then to the closed

position by hand.

6. Observe the TP sensor 1 and TP sensor 2 angle

parameters with a scan tool.

Does the scan tool indicate both angle parameters increasing
as the throttle plate is moved to WOT, and decreasing as the
plate is moved to the closed position?

Go to Step 8

Go to Step 15

1. Turn OFF the ignition.

2. Disconnect the throttle actuator control (TAC) module

harness connector containing the throttle actuator
control motor circuits.

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

4. Test the TAC motor circuits 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 17

Go to Step 9

Test each TAC motor 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 17

Go to Step 10

Test each TAC motor 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 17

Go to Step 11

1. Disconnect the other TAC module harness connector.

2. Test for a short between each TAC motor circuit and

all other TAC module circuits with a DMM. Refer to

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 P2101

Circuit Testing and Wiring Repairs in Wiring
Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 12

1. Turn OFF the ignition.

2. Connect the TAC module.

3. Connect a test lamp between the 2 TAC motor circuits

at the TAC motor harness connector.

4. Turn ON the ignition, with the engine OFF, and

observe the test lamp.

Did the test lamp illuminate briefly when the ignition was
turned ON?

Go to Step 13

Go to Step 15

Inspect for poor connections at the TAC motor harness
connector. 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 17

Go to Step 14

Replace the throttle body assembly. Refer to Throttle Body
Assembly Replacement .
Did you complete the replacement?

Go to Step 15

Inspect for poor connections at the TAC module harness
connectors. 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 17

Go to Step 16

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

Go to Step 17

1. Clear the DTCs with a scan tool.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

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 18

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

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