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Hummer H1 (2002+). Manual - part 74

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Transmission/Transfer Case 5-95

05745159

Turn the ignition “off” long enough to power down
PCM.

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

Install the jumper harness 05743837 on the engine
side of the 20-way connector.

With the engine off, turn the ignition switch to the
“Run” position.

Connect a test lamp from the jumper harness
05743837 cavity E to a good ground.

Does the test lamp illuminate?

—

Go to step 6.

Go to step 5.

Repair the open or short to ground in the ignition feed
circuit to the 1-2 shift solenoid.
Was a problem found and corrected?

—

Go to step 16.

—

Install a test lamp between cavity E and Cavity A
of the jumper harness.

Using the transmission output control function on
the scan tool, command the 1-2 shift solenoid
valve “On” and “Off” three times.

Does the test lamp illuminate when the shift solenoid is
commanded “On” and turn off when the shift solenoid
is commanded “OFF”?

—

Go to step 9.

Go to step 7.

Inspect/repair circuit 237 for an open or short to ground
condition.
Was a problem found?

—

Go to step 15.

Go to step 9.

Replace the PCM.
Is the replacement complete?

—

Go to step 15.

—

Turn ignition switch to the “Off” position.

Connect 05743837 Jumper Harness to transmis-
sion 20-way connector.

With DVOM and Connector Test Adapter Kit,
measure the resistance between terminals “A” and
“E.”

Is resistance within the indicated values?

19-31 ohms

Go to step 11.

Go to Step 10.

Remove oil pan and disconnect the internal wiring
harness from the 1-2 shift solenoid.

Measure 1-2 shift solenoid resistance.

Is resistance within the indicated values?

19-31 ohms

Go to step 13.

Go to step 14.

Using multimeter, measure resistance between termi-
nals “A” and ground and “E” and ground.

Are both readings greater than indicated value?

250K

Ω

Go to the diag-

nostic aids.

Go to step 12

DTC P0753 1-2 Shift Solenoid Valve Electrical (Cont’d)

Step

Action

Value

Yes

3-1-01

5-96

Transmission/Transfer Case

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Disconnect the internal wiring harness from 1-2
shift solenoid.

Using multimeter measure the resistance from
solenoid terminals to ground.

Are readings greater than value indicated?

250K

Ω

Go to step 13.

Go to step 14.

Inspect/repair the internal wiring harness for a short to
ground. Replace as necessary.

• Was a problem found and corrected?

—

Go to step 15.

—

Replace the 1-2 shift solenoid.

• Refer to 1-2 Shift Solenoid Replacement.

Is the replacement complete?

—

Go to step 15.

—

Preform the following procedure in order to verify the
repair:
1.

With the scan tool select “DTC”

Select “Clear Info.”

Select the parameters “1-2 Sol.” and “1-2 Sol.
Open/Shorted to GND”, and “1-2 Sol. Shorted to
Volts.”

Operate the vehicle under the following
conditions:

• The PCM commands the 1-2 shift solenoid valve

“On” and the “1-2 Sol. Shorted to Voltage” is
“NO”.

• The PCM commands the 1-2 shift solenoid valve

“Off” and the “1-2 Sol. Open/Shorted to GND”
is “No”.

• All conditions are met for 5 seconds.

Select Specific DTC.

Enter DTC P0753.

Has the test run and passed?

—

System OK.

Go to step 1.

DTC P0753 1-2 Shift Solenoid Valve Electrical (Cont’d)

Step

Action

Value

Yes

3-1-01

____________________________________________

Transmission/Transfer Case 5-97

05745159

DTC P0756 2-3 Shift Solenoid Valve Performance

Circuit Description

The 2-3 shift solenoid controls fluid acting on the 2-3 shift
valves. The solenoid is normally open and is used with the 1-2
shift solenoid to provide four different shift combinations.

This DTC detects a non 1st gear when 1st gear is commanded,
or 1st gear when 4th gear is commanded.

Conditions For Setting DTC

• No DTCs P0121, P0122, P0123, P0220, P0221, P0222,

P0223, P0225, P0226, P0227, P0228.

• No DTC P0722 or P0723.

• No sensor DTCs P0712 or P0713.

• No 4WD Lo DTC P1875.

• No DTC P1810.

• No shift solenoid electrical DTCs P0753 or P0758.

• No engine speed DTCs P0219.

• No DTCs P0716 or P0717.

• Engine running.

• Not in 4WD Low.

• Vehicle speed is greater than 6 km/h (4 mph).

• Throttle position is greater than 12%.

• Transmission fluid temperature is between 20° and

130°C (68° and 266° F).

• Engine torque is between 80 and 450 ft/lbs.

• Engine speed is less than 3750 rpm.

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

5-98

Transmission/Transfer Case

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Stuck On:

• Commanded Gear equals 1st and ratio equals 3rd for

greater than 2 seconds (Actual gear equals 4th).

• Commanded Gear equals 2nd and ratio equals 3rd for

greater than 2 seconds.

• Conditions occur for 4 occurrences.

Stuck Off:

• Commanded Gear equals 3rd and ratio equals 1st for

greater than 3 seconds.

• Condition occurs for 8 occurrences (continual rolling

counter).

Action Taken When DTC Sets

• The transmission will immediately land to 2nd gear.

• The PCM will command maximum line pressure.

• The PCM will freeze shift adapts.

• The PCM will illuminate the warning lamp.

Conditions For Clearing DTC

• For California emission vehicles the PCM will turn the

lamp after three consecutive ignition cycles without a
failure reported.

• The DTC can be cleared by using the scan tool.

• The PCM will cancel the DTC default actions when the

fault no longer exists and the ignition is cycled “off'
long enough to power down the PCM.

Diagnostic Aids

• Verify that the transmission meets the specifications in

the 4L80-E shift speed chart.

• Other internal transmission failures may cause more

than one shift to occur.

• Customer may complain of an engine over-rev condi-

tion or neutral in 4th gear.

• If any engine DTCs or TP Sensor codes are present di-

agnose and clear these DTCs first. Then check to see if
the transmission DTCs have reset.

Test Description

The numbers below refer to the diagnostic chart.

2. This test checks the function of the PSA.
3. This test checks for selected gear ratio vs. a ratio not

obtainable under normal driving conditions.

4L80-E CHART

Gear

1-2 Shift
Solenoid

2-3 Shift
Solenoid

OFF

Content .. 72 73 74 75 ..