Hummer H2. Manual — part 2388

2004 TRANSMISSION

Automatic Transaxle, 4L60-E/4L65-E (Diagnostic Information & Procedures) - Hummer H2

AUTOMATIC TRANSAXLE (DIAGNOSTIC INFORMATION & PROCEDURES)

DIAGNOSTIC STARTING POINT - AUTOMATIC TRANSMISSION

Begin the system diagnosis with Diagnostic System Check - Engine Controls in Engine Controls - 6.0L
(LQ4). The Diagnostic System Check provides the following information:

z

The identification of the control module or modules which commands the system.

z

The ability of the control module or modules to communicate through the serial data circuit.

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The identification and status of stored diagnostic trouble codes (DTCs).

The use of the Diagnostic System Check - Engine Controls in Engine Controls - 6.0L (LQ4) identifies the
correct procedure for diagnosing the system and the procedure location.

Symptoms

When it has been determined through Diagnostic System Check - Engine Controls in Engine Controls - 6.0L
(LQ4) that no DTCs are present, begin symptom diagnosis by reviewing the Transmission Component and
System Description . Reviewing the Transmission Component and System Description information enables
you to understand the operation of the system. This helps you determine if the condition described by the
customer is normal or if a malfunction exists. If it is determined that a malfunction exists, identify the concern
by referring to the Symptoms - Automatic Transmission table. The Symptoms - Automatic Transmission
table provides common diagnostic categories which relate directly to diagnostic information or procedures.

DIAGNOSTIC SYSTEM CHECK - AUTOMATIC TRANSMISSION

Circuit Description

The Automatic Transmission Diagnostic System Check is an organized approach to identify a problem created
by an automatic transmission. The Diagnostic System check is the diagnostic starting point for an automatic
transmission complaint. The Diagnostic System Check directs you to the next logical step for diagnosing a
transmission concern. Perform this check only if there is a driveability complaint or if you have been directed
here from another service information section.

Follow the table to help reduce diagnostic time and help prevent unnecessary replacement of good parts.

Diagnostic Aids

IMPORTANT:

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Do not clear the DTC unless directed by a diagnostic procedure. Clearing
the DTCs will erase all Freeze Frame and Failure Records stored in PCM
memory.

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle, 4L60-E/4L65-E (Diagnostic Information & Procedures) - Hummer H2

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle, 4L60-E/4L65-E (Diagnostic Information & Procedures) - Hummer H2

z

Use a scan tool that is known to function correctly. If necessary, test the scan tool on another vehicle.

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Ensure the scan tool contains the most current file available.

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The scan tool will display a loss of communication error message under the following conditions:

{

PCM power is interrupted

{

The ignition switch is turned OFF

{

The battery voltage level is very low

{

A poor connection at the diagnostic link connector (DLC)

Test Description

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

1: This step determines if the scan tool is receiving power through the DLC connector.

2: The MIL should illuminate whenever the ignition is ON and the engine is not running.

3: This step determines if the PCM is transmitting class 2 serial data to the DLC and that the class 2 data
circuit is not open or shorted.

4: This step determines if a DTC is current or stored in history.

Diagnostic System Check - Automatic Transmission

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Poor engine performance can sometimes be diagnosed as a transmission
driveability condition. In order to avoid mis-diagnosis of the automatic
transmission, always perform the Diagnostic System Check - Engine
Controls in Engine Controls - 6.0L (LQ4).

Step

Action

Value

(s)

Yes

No

1

1. Install a scan tool.

IMPORTANT:

Check for applicable service bulletins
before proceeding with this test.
Perform this test only if there is a
driveability complaint or if you have
been directed to this table from
another section in the service
information.

IMPORTANT:

Do not turn the ignition OFF when
performing this diagnostic procedure.
Do not clear the DTCs unless
instructed by this diagnostic
procedure.

-

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle, 4L60-E/4L65-E (Diagnostic Information & Procedures) - Hummer H2

SCAN TOOL OUTPUT CONTROLS

Scan Tool Output Controls

2. Turn ON the ignition, with the engine

OFF.

Does the scan tool turn ON?

Go to Step 2

Go to Diagnostic Starting

Point - Data Link

Communications in Data

Link Communications

2

Is the MIL ON?

-

Go to Step 3

Go to Malfunction

Indicator Lamp (MIL)

Inoperative in Engine

Controls - 6.0L (LQ4)

3

Attempt to establish communication with the
PCM.
Does the scan tool communicate with the
PCM?

-

Go to Step 4

Go to Diagnostic Starting

Point - Data Link

Communications in Data

Link Communications

4

Use the scan tool Capture Info function in
order to save or capture (Store Info) any DTC
Information.Are there any DTCs present?

IMPORTANT:

Diagnostic Trouble Codes (DTCs), engine
performance, and transmission default
actions can greatly affect the transmission
performance. Ensure that these items are
not the cause of a transmission concern.

-

Go to

Diagnostic

Trouble Code

(DTC)

List/Type

Go to Symptoms -

Automatic Transmission

Scan Tool

Output Control

Additional

Menu

Selections

Description

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The PCM commands the 1-2 shift solenoid valve ON and OFF.
The scan tool 1-2 Sol. parameter should match the commanded
state. The scan tool Commanded Gear parameter should
correspond with the shift solenoid combination. Refer to Shift
Solenoid Valve State and Gear Ratio table.

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When the ignition is ON, and the engine is OFF, there are no
limits to this control. The solenoid remains ON until commanded
OFF, and vice versa. When the output control is exited, the
solenoid state is determined by the PCM.

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When the engine is running, the following control limits apply:

{

Only sequential gear changes are allowed. For example, 1st
to 3rd is not allowed. If a non-sequential gear change is
attempted, the message "Non-sequential gear changes not
allowed. Gear changes must be in order" appears on the
scan tool display.

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle, 4L60-E/4L65-E (Diagnostic Information & Procedures) - Hummer H2

1-2 Solenoid

-

{

The vehicle speed must be below a calibrated value. If the
vehicle speed is too high, the message "Vehicle speed too
high" appears on the scan tool display.

{

The engine speed must be below a calibrated value. If the
engine speed is too high, the message "Engine speed too
high" appears on the scan tool display.

{

Downshifts are allowed only when the vehicle speed is
below a calibrated value. If the vehicle speed is too high,
the message "Eng. is on and veh. speed too hi for 3-2 or 2-1
downshift" appears on the scan tool display.

{

The gear requested may not be greater than the current
selected transmission range (PRNDL). For example, 3rd
gear is not allowed if the transmission range is D2. If the
gear requested is greater than the current selected
transmission range, the message "Eng. running and gear
request is greater than the current TR" appears on the scan
tool display.

{

The solenoid remains ON until commanded OFF, and vice
versa. When the output control is exited, the solenoid state
is determined by the PCM.

2-3 Solenoid

-

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The PCM commands the 2-3 shift solenoid valve ON and OFF.
The scan tool 2-3 Sol. parameter should match the commanded
state. The scan tool Commanded Gear parameter should
correspond with the shift solenoid combination. Refer to Shift
Solenoid Valve State and Gear Ratio table.

z

When the ignition is ON, and the engine is OFF, there are no
limits to this control. The solenoid will remain ON until
commanded OFF, and vice versa. When the output control is
exited, the solenoid state is determined by the PCM.

z

When the engine is running, the following control limits apply:

{

Only sequential gear changes are allowed. For example, 1st
to 3rd is not allowed. If a non-sequential gear change is
attempted, the message "Non-sequential gear changes not
allowed. Gear changes must be in order" appears on the
scan tool display.

{

The vehicle speed must be below a calibrated value. If the
vehicle speed is too high, the message "Vehicle speed too
high" appears on the scan tool display.

{

The engine speed must be below a calibrated value. If the
engine speed is too high, the message "Engine speed too
high" appears on the scan tool display.

{

Downshifts are allowed only when the vehicle speed is
below a calibrated value. If the vehicle speed is too high,
the message "Eng. is on and veh. speed too hi for 3-2 or 2-1

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle, 4L60-E/4L65-E (Diagnostic Information & Procedures) - Hummer H2