Hummer H2. Manual — part 2500

8

Measure the resistance from terminal E to ground, and
from terminal U to ground.
Do both readings measure greater than the specified
value?

250 K

ohm

Go to

Intermittent

Conditions in

Engine Controls -

6.0L (LQ4)

Go to Step 10

9

1. Disconnect the AT wiring harness assembly

from the TCC PWM solenoid valve.

2. Measure the resistance of the TCC PWM

solenoid valve.

Does the resistance measure within the specified
range?

10-15

ohm

Go to Step 17

Go to Step 18

10

1. Disconnect the AT wiring harness assembly

from the TCC PWM solenoid valve.

2. Measure the resistance from each of the

component terminals to ground.

Do both readings measure greater than the specified
value?

250 K

ohm

Go to Step 17

Go to Step 18

11 Test the Ignition 0 voltage circuit of the TCC PWM

solenoid valve for a short to ground between the fuse
block and the AT inline 20-way connector.Refer to
Testing for Short to Ground and extxref
document="029_body-21" filetype="sgml"
extrefid="i162420">Wiring Repairs in Wiring
Systems.Did you find and correct the condition?

IMPORTANT:

The condition that affects this circuit may exist in
other connecting branches of the circuit. Refer to
Power Distribution Schematics in Wiring Systems
for complete circuit distribution.

-

Go to Step 20

Go to Step 12

12

Test the Ignition 1 voltage circuit of the TCC PWM
solenoid valve for a short to ground between the AT
inline 20-way connector and the TCC PWM solenoid
valve.Refer to Testing for Short to Ground in
Wiring Systems.Did you find a short to ground
condition?

IMPORTANT:

The condition that affects this circuit may exist in
other connecting branches of the circuit. Refer to
Power Distribution Schematics in Wiring Systems
for complete circuit distribution.

-

Go to Step 17

Go to Step 13

1. Test each solenoid for a short to ground.

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

13

2. Replace the faulty solenoid as necessary.

Did you complete the replacement?

-

Go to Step 20

-

14

Test the Ignition 0 voltage circuit of the TCC PWM
solenoid valve for an open.Refer to Testing for
Continuity and extxref document="029_body-21"
filetype="sgml" extrefid="i162420">Wiring Repairs
in Wiring Systems.Did you find and correct the
condition?

IMPORTANT:

The condition that affects this circuit may exist in
other connecting branches of the circuit. Refer to
Power Distribution Schematics in Wiring Systems
for complete circuit distribution.

-

Go to Step 20

-

15

Test the control circuit of the TCC PWM solenoid
valve for a short to ground between the PCM
connector C2 and the AT inline 20-way connector.
Refer to Testing for Short to Ground and extxref
document="029_body-21" filetype="sgml"
extrefid="i162420">Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

-

Go to Step 20

Go to Step 19

16

Test the control circuit of the TCC PWM solenoid
valve for an open or short to voltage between the
PCM connector C2 and the AT inline 20-way
connector.
Refer to Circuit Testing and extxref
document="029_body-21" filetype="sgml"
extrefid="i162420"> Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

-

Go to Step 20

Go to Step 19

17

Replace the AT wiring harness assembly.
Refer to Valve Body and Pressure Switch
Replacement .
Did you complete the replacement?

-

Go to Step 20

-

18

Replace the TCC PWM solenoid valve.
Refer to Valve Body and Pressure Switch
Replacement .
Did you complete the replacement?

-

Go to Step 20

-

19

Replace the PCM.
Refer to Powertrain Control Module (PCM)
Replacement in Engine Controls - 6.0L (LQ4).
Did you complete the replacement?

-

Go to Step 20

-

Perform the following procedure in order to verify the
repair:

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

DTC P2771

20

1. Select DTC.

2. Select Clear Info.

3. Drive the vehicle in D4 with the TCC On.

Ensure that the following conditions are met:

z

The PCM commands the TCC PWM
solenoid valve ON, and the voltage
feedback drops to zero.

z

The PCM commands the TCC PWM
solenoid valve OFF, and the voltage
feedback increases to B+.

z

All conditions are met for 5 seconds.

4. Select Specific DTC.

5. Enter DTC P2761.

Has the test run and passed?

-

Go to Step 21

Go to Step 2

21

With the scan tool, observe the stored information,
capture info, and DTC Info.
Does the scan tool display any DTCs that you have
not diagnosed?

-

Go to Diagnostic

Trouble Code

(DTC) List in

Engine Controls -

6.0L (LQ4)

System OK

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

Fig. 24: Four Wheel Drive (4WD) Low Circuit Diagram
Courtesy of GENERAL MOTORS CORP.

Circuit Description

The four wheel drive (4WD) low circuit consists of the powertrain control module (PCM), a transfer case
control module and the circuit wiring. The transfer case control module controls the 4WD low signal on the low
signal circuit. When the operator selects 4WD low, the transfer case control module grounds the signal circuit,
and the 4WD low signal voltage on the circuit changes from ignition voltage to zero volts. The PCM then
compensates for transfer case gear reduction in the transmission output shaft speed (OSS) sensor signal. The
PCM uses the transmission OSS sensor signal to adjust shift points, line pressure and torque converter clutch
(TCC) scheduling.

When the PCM detects a continuous open, short to ground or short to power in the 4WD low circuit, then DTC
P2771 sets. DTC P2771 is a type B DTC.

Conditions for Running the DTC

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2