Hummer H2. Manual - part 1685

transistors change, this DTC sets. If this DTC does not fail this ignition, continue to monitor this DTC
status while moving related harnesses and connectors.

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

DTC U0107

Step

Action

Values

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

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

2. Remove the cover from the underhood

electrical center.

3. Test both sides of the ETC fuse with a test

lamp connected to ground.

Does the test lamp illuminate on at least one side
of the fuse?

Go to Step 3

Go to Ignition

Relay Diagnosis

1. Turn OFF the ignition

2. Test for voltage at the ETC fuse with a test

lamp connected to ground.

Does the test lamp illuminate?

Go to Step 22

Go to Step 4

Connect a scan tool.
Is DTC P0604 also set?

Go to DTC P0601-

P0607, P1600,
P1621, P1627,
P1680, P1681,

P1683, or P2610

Go to Step 5

1. Start the engine.

2. Increase the engine speed to 3,000 RPM, if

possible.

3. Monitor the DTC Info option using the scan

tool.

Does the scan tool indicate this DTC failed this

IMPORTANT:

If the Driver Information Center is displaying
Reduced Engine Power, go to Step 6.

Go to Diagnostic

2004 Hummer H2

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

Hummer H2

ignition?

Go to Step 6

Aids

1. Turn OFF the ignition.

2. Disconnect the throttle actuator motor

harness connector.

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

4. Test for voltage at both throttle actuator

motor control circuits with a DMM.

Does the DMM indicate voltage on both circuits
above the specified value?

1 V

Go to Step 12

Go to Step 7

1. Turn OFF the ignition.

2. Disconnect the throttle actuator control

(TAC) module connectors.

3. Test both throttle actuator motor control

circuits for continuity to ground with a
DMM.

Does the DMM indicate continuity to ground?

Go to Step 10

Go to Step 8

1. Turn OFF the ignition.

2. Remove the ETC fuse.

3. Test the TAC side of the fuse terminal for

continuity to ground with a DMM. Refer to
Diagnostic Aids for terminal identification
table.

Does the DMM indicate continuity to ground?

Go to Step 9

Go to Step 11

1. Disconnect the TAC module 16-way harness

connector.

2. Test the TAC side of the fuse terminal 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 28

Go to Step 24

1. Disconnect the TAC module 16-way harness

connector.

2. Test the throttle actuator motor control

circuits for a short to ground at the TAC
module 16-way harness connector with a
DMM. Refer to Circuit Testing and Wiring
Repairs in Wiring Systems.

2004 Hummer H2

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

Hummer H2

Did you find and correct the condition?

Go to Step 28

Go to Step 24

1. Turn OFF the ignition.

2. Disconnect the TAC module 16-way harness

connector.

3. Test the TAC module ignition feed 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 28

Go to Step 24

1. Turn OFF the ignition.

2. Disconnect the TAC module 16-way

connector.

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

4. Test for a short to voltage at both throttle

actuator motor control circuits with a DMM.
Refer to Circuit Testing and Wiring
Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 13

1. Turn OFF the ignition.

2. Disconnect the TAC module 10-way harness

connector.

3. Test for a short between each throttle

actuator motor control 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 28

Go to Step 14

Test for an open or high resistance in the TAC
module ground circuit with a DMM. Refer to
Circuit Testing and Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

Go to Step 28

Go to Step 15

Test for voltage on the serial data circuits at the
TAC module 16-way harness connector with a
DMM.
Does the DMM indicate voltage within the
specified values for both circuits?

0-4.5

Go to Step 16

Go to Step 18

1. Turn OFF the ignition.

2. Test both serial data circuits at the TAC

module 16-way harness connector for

2004 Hummer H2

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

Hummer H2

continuity to ground with a DMM.

Does the DMM indicate OL for both circuits?

Go to Step 20

Go to Step 17

1. Disconnect the powertrain control module

(PCM) connector containing the TAC
module serial data circuits.

2. Test both serial data circuits at the TAC

module 16-way connector 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 28

Go to Step 18

Test for a short between both serial data circuits
and all other circuits at the PCM and TAC module
harness connectors with a DMM. Refer to Circuit
Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 28

Go to Step 19

Test for a short to voltage on both serial data
circuits at the TAC module 16-way connector with
a DMM. Refer to Circuit Testing and Wiring
Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 28

Go to Step 25

1. Disconnect the PCM connector that contains

the TAC module serial data circuits.

2. Test each serial data circuit between the

TAC module 16-way harness connector and
the PCM harness connector 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 28

Go to Step 21

1. Connect the PCM.

2. Turn ON the ignition.

3. Test for voltage on the serial data circuit at

the TAC module 16-way harness connector
with a DMM.

Does the DMM indicate voltage at the specified
value?

0 V

Go to Step 25

Go to Step 24

1. Turn OFF the ignition.

2. Disconnect the 16-way TAC module harness

2004 Hummer H2

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

Hummer H2

Content .. 1683 1684 1685 1686 ..