Content .. 76 77 78 79 ..

Hummer H1 (2002+). Manual - part 78

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Transmission/Transfer Case 5-111

05745159

Did the 2-3 shift time exceed the specified value?

1.25 seconds

Go to

Step 13

Go to Step 11

Did the 1-2 shift time exceed the specified value?

1.25 seconds

Go to

Step 14

—

Inspect the following 3-4 shift circuit components:

• 4th Gear Clutch Plates

• 4th Gear Clutch Seals

Refer to Unit Repair.
Did you find and correct a problem?

—

Go to

Step 15

—

Inspect the following 2-3 shift circuit components:

• Turbine Shaft Seals

• Forward Clutch Plates

• Forward Clutch Seals

• Direct Clutch Plates

• Direct Clutch Seals

Refer to Unit Repair.
Did you find and correct a problem?

—

Go to

Step 15

—

Inspect the following 1-2 shift circuit components:

• Low Roller Clutch

• Intermediate Clutch Plates

• Intermediate Clutch Seals

• Intermediate Sprag Clutch

• Over drive Roller Clutch

Refer to Unit Repair.
Did you find and correct a problem?

—

Go to

Step 15

—

Inspect the Torque Converter for “ballooning”.
Did you find a problem?

—

Go to

Step 16

Go to Step 17

Replace the Torque Converter.
Is the replacement complete?

—

Go to

Step 17

—

In order to verify your repair, perform the following procedure:
1.

Select DTC.

Select Clear Info.

Turn the ignition key to the RUN position.

Review the scan tool DTC info.

Select Specific DTC. Enter DTC P1811.

Has the test run and passed?

—

System

OK.

Begin diagnostic

again. Go to Step

DTC P1811 Maximum Adapt and Long Shift (Cont’d)

Step

Action

Value

Yes

5-112

Transmission/Transfer Case

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DTC P1860 Torque Converter Clutch Pulse
Width Modulation Solenoid Electrical

Circuit Description

The Torque Converter Clutch Pulse Width Modulation Sole-
noid Valve (TCC PWM Sol. Valve) controls fluid acting on the
converter clutch valve, which then controls TCC apply and re-
lease. The TCC PWM Sol. Valve attaches to the control valve
body within the transmission. Ignition voltage goes directly to
the TCC PWM Sol. Valve. The Powertrain Control Module
(PCM) controls the TCC PWM Sol. Valve by providing a
ground path on circuit 418. The current flows through the TCC
PWM Sol. Valve coil according to the duty cycle (percentage
of ON and OFF time). The TCC PWM Sol. Valve provides a
smooth engagement of the torque converter clutch by operating
on a duty cycle percent of ON time.

If the PCM detects a continuous open or short to ground in the
TCC PWM Sol. Valve circuit or the TCC PWM Sol. Valve,
then DTC P1860 sets. DTC P1860 is a type A DTC.

Conditions For Setting DTC

System voltage is 10-16.5 volts.

The engine is running more than 475 RPM for greater
than 7 seconds.

No shift solenoid DTCs P0751, P0753, P0756, and
P0758.

Commanded gear is D1.

All of the above conditions are met, and one of the
following conditions is met for 4.3 seconds out of 5
seconds.

• The PCM commands the solenoid OFF, and the voltage

remains below (zero volts).

• The PCM commands the solenoid to ON (100%) and

the voltage remains high (B+).

Action Taken When DTC Sets

•

The PCM inhibits TCC engagement.

•

The PCM inhibits 4th gear if in hot mode.

•

The PCM illuminates the Malfunction Indicator Lamp
(MIL).

FUSE 2A

10A

EXTERIOR

C33-F

351 PK

C34

C32-G

C32-F

C32-E

C32-D

C32-C

C32-J

C32-H

C34-E

C27-C15

C27-C7

C28-C5

C28-C6

C28-C4

C29-B12

C27-C9

265 LB

264 RD

924 TN

315 YL

237 LG

359 BK

923 BR

PRESSURE

CONTROL

SOLENOID

(PCS)

TORQUE

CONVERTER

CLUTCH

SOLENOID

(TCC)

1-2 SHIFT
SOLENOID
(1-2)

2-3 SHIFT
SOLENOID
(2-3)

TRANSMISSION

FLUID

TEMPERATURE

SENSOR

(TFT)

PCS

LOW

PCS

HIGH

TCC PWM

SOLENOID

CONTROL

2-3 SS

CONTROL

1-2 SS

CONTROL

SENSOR

GROUND

TFT

SENSOR

SIGNAL

POWERTRAIN

CONTROL

MODULE

(PCM)

HOT IN RUN
AND START

9 - S 1 2 - 0 6 7

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Transmission/Transfer Case 5-113

05745159

Conditions For Clearing DTC

The PCM turns OFF the MIL after three consecutive igni-
tion cycles without a failure reported.

A scan tool can clear the DTC from the PCM history. The
PCM clears the DTC from the PCM history if the vehicle
completes 40 warm-up cycles without a failure reported.

The PCM cancels the DTC default actions when the fault
no longer exists and the ignition is OFF long enough in
order to power down the PCM.

Diagnostic Aids

•

Inspect the wiring for poor electrical connections at the
PCM.

•

Inspect the wiring for poor electrical connections at the
transmission 20-way connector. Look for the following
problems:

• A bent terminal

• A backed out terminal

• A damaged terminal

• Poor terminal tension

• A chafed wire

• A broken wire inside the insulation

•

When diagnosing for an intermittent short or open, mas-
sage the wiring harness while watching the test equipment
for a change.

•

First diagnose and clear any engine DTCs that are present.
Then inspect for any transmission DTCs that may have reset.

Test Description

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

4. This step tests for voltage to the TCC PWM Sol. Valve.

6. This step tests the ability of the PCM and wiring to control

the ground circuit.

8. This step tests the resistance of the TCC PWM Sol. Valve

and the internal wiring harness

12. If the internal wiring harness is open, do not repair the in-

ternal wiring harness. You must replace the Automatic
Transmission Wiring Harness Assembly

Section 5 Transmission/Trans er Case

5-114

Transmission/Transfer Case

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DTC P1860 Torque Converter Clutch Pulse Width Modulation Solenoid Electrical

Step

Action

Value

Yes

Was the Powertrain On-Board Diagnostic (OBD) Sys-
tem Check performed?

—

Go to Step 2

Go to Power-

train OBD

System Check

Install the scan tool (Tech 1).

With the engine OFF, turn the ignition switch to
the RUN position.

Important: Before clearing the DTCs, use the scan
tool in order to record the Freeze Frame and Fail-
ure Records for reference. The Clear Info function
will erase the data

Record the DTC Freeze Frame and Failure
Records.

If DTCs P0753, P0758, or P1860 are set, inspect
the fuse.

Is the fuse blown?

—

Go to Step 3

Go to Step 4

Inspect circuit 1020, the TCC PWM Sol. Valve and the
internal wiring harness for a short to ground. Refer to
Electrical Diagnosis, Section 8.
Did you find and correct a problem?

—

Go to Step 17

—

Turn the ignition OFF.

Disconnect the transmission 20-way connector
(additional DTCs may set).

Install the J–39775 Jumper Harness on the engine
harness connector.

With the engine off, turn the ignition to the RUN
position.

Connect a test lamp from the J–39775 Jumper Har-
ness cavity E to ground.

Is the test lamp ON?

—

Go to Step 6

Go to Step 5

Repair the open or high resistance located in ignition
voltage feed circuit 1020 to the TCC PWM Sol. Valve.
Refer to Electrical Diagnosis, Section 8.
Is the repair complete?

—

Go to Step 17

—

Install the test lamp from cavities E to S of the J–
39775 Jumper Harness.

Use the scan tool in order to command the TCC
PWM Sol. Valve ON and OFF three times.

Does the test lamp turn ON when you command the
TCC PWM Sol. Valve ON, and does the lamp turn OFF
when you command the TCC PWM Sol. Valve OFF?

—

Go to Step 8

—

Inspect and repair circuit 418 for an open or short to
ground. Refer to Electrical Diagnosis, Section 8.
Did you find a problem?

—

Go to Step 17

Go to Step 9

Install the J–39775 Jumper Harness on the trans-
mission 20-way connector.

Measure the resistance between terminals E and S.
Use the J–39200 DVOM and the J–35616-A Con-
nector Test Adapter Kit (Both covered in

Electrical

Section 12).

Is the resistance within the specified values?

10-15

Go to Step 11

Go to Step 10

Content .. 76 77 78 79 ..