Hummer H2. Manual — part 2450

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Harsh, soft or slipping shifts

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Harsh, soft or delayed engagement

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Shift shudder, flare or tie-up

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Refer to Slipping or Harsh 1-2 Shift .

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Refer to No 2-3 Shift or 2-3 Shift Slips, Rough
or Hunting .

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Refer to No 3-4 Shift, Slips or Rough 3-4
Shift .

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Refer to Harsh Garage Shift .

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Refer to Delay in Drive and Reverse .

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Refer to 3-2 Flare or Tie-Up .

Shift Pattern:
This category contains the following topics:

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One forward gear only

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Two forward gears only

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Gear missing or slipping

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No upshift or slipping upshift

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No downshifts

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Non-First gear start

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Refer to First Gear Range Only - No Upshift .

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Refer to Third Gear Only .

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Refer to Second/Third Gear Only or
First/Fourth Gears Only .

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Refer to Slips in First Gear .

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Refer to Slipping or Harsh 1-2 Shift .

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Refer to No 2-3 Shift or 2-3 Shift Slips, Rough
or Hunting .

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Refer to No 3-4 Shift, Slips or Rough 3-4
Shift .

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Refer to No Part Throttle or Delayed
Downshifts .

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Refer to Second Gear Start .

Shift Speed Diagnosis:
This category contains the following topic:
Inaccurate or inconsistent shift points

Refer to Inaccurate Shift Points .

Torque Converter Diagnosis:
This category contains the following topics:

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Torque converter diagnosis

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TCC does not apply

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TCC does not release

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TCC apply/release quality

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Refer to Torque Converter Diagnosis
Procedure .

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Refer to No Torque Converter Clutch (TCC)
Apply (300 RPM Slip) .

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Refer to No Torque Converter Clutch (TCC)
Release .

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Refer to Torque Converter Clutch (TCC)
Shudder .

Indicator On or Message Center Displays
Message:
This category contains the following topics:

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4WD light does not illuminate

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Tow/haul light does not illuminate

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Message Center displays "Trans Fluid
Hot"

or

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Refer to DTC P2771 .

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Refer to Tow/Haul Switch/Indicator Always
On or Inoperative .

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Refer to Transmission Fluid Checking
Procedure .

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Refer to Transmission Overheats .

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle - 4L60-E/4L65-E (Troubleshooting)

RANGE SELECTOR DISPLAYS INCORRECT RANGE

Fig. 1: Transmission Range (TR) Switch Diagram
Courtesy of GENERAL MOTORS CORP.

Circuit Description

The transmission range (TR) switch is part of the park/neutral position (PNP) and back-up lamp switch
assembly, which is externally mounted on the transmission manual shaft. The TR switch contains four internal
switches that indicate the transmission gear range selector lever position. The PCM supplies ignition voltage to
each switch circuit. As the gear range selector lever is moved, the state of each switch may change, causing the
circuit to open or close. An open circuit or switch indicates a high voltage signal. A closed circuit or switch
indicates a low voltage signal. The PCM detects the selected gear range by deciphering the combination of the

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Message Center displays "Trans Hot...Idle
Engine"

If symptom is not found

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Refer to Transmission Fluid Checking
Procedure .

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Refer to Road Test Procedure .

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Refer to Line Pressure Check Procedure .

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle - 4L60-E/4L65-E (Troubleshooting)

voltage signals. The PCM compares the actual voltage combination of the switch signals to a TR switch
combination chart stored in memory.

Diagnostic Aids

Refer to the Transmission Range Switch Logic table for valid combinations of switch signal circuits A, B, C
and Parity. On the table, HI indicates an ignition voltage signal. LOW indicates a zero voltage signal.

Test Description

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

4: By disconnecting the TR switch, the ground path of all TR switch circuits is removed and the PCM
should recognize all circuits as open. The scan tool should display HI for all range signal states.

5: This step tests the TR switch wiring for an open or the lack of the signal voltage from the PCM.

6: This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper
wire. When grounded, the scan tool range signal states should change to LOW.

7: This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper
wire. When grounded, the scan tool range signal states should change to LOW.

8: This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper
wire. When grounded, the scan tool range signal states should change to LOW.

9: This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper
wire. When grounded, the scan tool range signal states should change to LOW.

Range Selector Displays Incorrect Range

Step

Action

Value

(s)

Yes

No

1

1. Install a scan tool.

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

3. Select TR Sw. on the scan tool.

4. With the scan tool, observe the TR Sw. display

while selecting each transmission range: P, R, N,
D4, D3, D2 and D1.

Does each selected transmission range match the scan
tool TR Sw. display?

-

Go to Step 2

Go to

Step 3

2

Observe the IPC gear range display while selecting each
transmission range: P, R, N, D4, D3, D2, D1.
Does each selected transmission range match the IPC
display?

-

Go to Intermittent

Conditions in Engine

Controls - 6.0L (LQ4)

Go to

Step

16

3

With the scan tool, observe the TR Sw. A/B/C/P
display.
Does the scan tool TR Sw. A/B/C/P parameter indicate
HI for all range signal states?

-

Go to Step 13

Go to

Step 4

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle - 4L60-E/4L65-E (Troubleshooting)

4

1. Turn OFF the ignition.

2. Disconnect the TR switch connector.

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

Does the scan tool TR Sw. A/B/C/P parameter indicate
HI for all range signal states?

-

Go to Step 5

Go to

Step

10

5

1. Using the DMM and the J 35616 GM Terminal

Test Kit, measure the voltage from terminal 8 of
the TR switch connector to ground.

2. Measure the voltage from terminal 4 of the TR

switch connector to ground.

3. Measure the voltage from terminal 6 of the TR

switch connector to ground.

4. Measure the voltage from terminal 5 of the TR

switch connector to ground.

Does the voltage measure within the specified value at
all four terminals?

10-12

V

Go to Step 6

Go to

Step

11

6

Connect a fused jumper wire from terminal 8 of the TR
switch connector, signal circuit A, to ground while
monitoring the scan tool TR Sw. A/B/C/P parameter.
When signal circuit A is grounded, do any other signal
circuits indicate LOW?

-

Go to Step 12

Go to

Step 7

7

Connect a fused jumper wire from terminal 5 of the TR
switch connector, signal circuit B, to ground while
monitoring the scan tool TR Sw. A/B/C/P parameter.
When signal circuit B is grounded, do any other signal
circuits indicate LOW?

-

Go to Step 12

Go to

Step 8

8

Connect a fused jumper wire from terminal 4 of the TR
switch connector, signal circuit C, to ground while
monitoring the scan tool TR Sw. A/B/C/P parameter.
When signal circuit C is grounded, do any other signal
circuits indicate LOW?

-

Go to Step 12

Go to

Step 9

9

Connect a fused jumper wire from terminal 6 of the TR
switch connector, signal circuit P, to ground while
monitoring the scan tool TR Sw. A/B/C/P parameter.
When signal circuit P is grounded, do any other signal
circuits indicate LOW?

-

Go to Step 12

Go to

Step

13

10

Test the signal circuits of the TR switch that did not
indicate HI for a short to ground.
Refer to Testing for Short to Ground and Wiring
Repairs in Wiring Systems.
Did you find and correct the condition?

-

Go to Step 17

Go to

Step

15

Test the signal circuits of the TR switch that did not

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle - 4L60-E/4L65-E (Troubleshooting)