Hummer H2. Manual - part 2482

DTC P0741

an open or short to power 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 17

Go to Step 16

Replace the AT wiring harness assembly, this
includes the TCC solenoid valve.
Refer to Valve Body and Pressure Switch
Replacement .
Did you complete the replacement?

Go to Step 17

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

Go to Step 17

Perform the following procedure in order to verify the
repair:

1. Select DTC.

2. Select Clear Info.

3. Drive the vehicle in D4 with the TCC ON and

OFF. Ensure that the following conditions are
met:

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

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

All conditions met for 5 seconds.

4. Select Specific DTC.

5. Enter DTC P0740.

Has the test run and passed?

Go to Step 18

Go to Step 2

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. 11: Torque Converter Clutch (TCC) Fluid Diagram
Courtesy of GENERAL MOTORS CORP.

Circuit Description

The torque converter clutch (TCC) solenoid valve is a normally-open exhaust valve that is used with the torque
converter clutch pulse width modulation (TCC PWM) solenoid in order to control fluid acting on the converter
clutch apply valve. The TCC solenoid valve attaches to the transmission case assembly extending into the pump
cover. When grounded, energized, by the powertrain control module (PCM), the TCC solenoid valve stops
converter signal oil from exhausting. This causes converter signal oil pressure to increase and move the
converter clutch apply valve against spring force and into the apply position. In this position, release fluid is
open to an exhaust port and converter feed fluid fills the apply circuit. The converter feed fluid applies the TCC.
When the PCM no longer provides a ground path, the TCC solenoid valve de-energizes and apply fluid
exhausts, releasing the TCC.

When the PCM detects a high TCC slip speed when the PCM commands the TCC ON, then DTC P0741 sets.
DTC P0741 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

No TCC DTC P0742.

No VSS assembly DTCs P0502 or P0503.

No TCC solenoid valve DTC P0740.

No TFP manual valve position switch DTC P1810.

No TPS high or low DTCs P1120 or P1220.

The transmission fluid temperature is 20-150°C (68-302°F).

The TP angle is 20-99 percent.

The engine speed is greater than 450 RPM for 5 seconds.

The engine is not in fuel cutoff.

The speed ratio is 0.89-1.02, the speed ratio is engine speed divided by output speed.

The gear range is D2, D3 or D4.

The gear range does not change within 6 seconds.

The TCC is commanded ON for 5 seconds.

The TCC duty cycle is 75 percent or greater.

Conditions for Setting the DTC

DTC P0741 sets if the following condition occurs three times.

The TCC slip speed is 130 RPM or greater for 20 seconds.

Action Taken When the DTC Sets

The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which
the Conditions for Setting the DTC are met.

The PCM freezes transmission adapt functions.

The PCM commands maximum line pressure.

The PCM inhibits 4th gear in Hot Mode.

The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM
stores this information as Freeze Frame and Failure Records.

The PCM stores DTC P0741 in PCM history during the second consecutive trip in which the Conditions
for Setting the DTC are met.

Conditions for Clearing the MIL/DTC

The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and
passes.

A scan tool can clear the MIL/DTC.

The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an
emission-related diagnostic fault occurring.

The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power

2004 Hummer H2

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

down the PCM.

Diagnostic Aids

Contamination may cause the TCC apply valve to stick in the valve body.

There may be internal damage in the torque converter causing the no TCC apply.

Test Description

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

2: This step inspects for excessive TCC slip when the TCC is commanded ON.

3: This step inspects for possible causes of no TCC apply.

DTC P0741

Step

Action

Value

(s)

Yes

Did you perform the Diagnostic System Check
- Engine Controls?

Go to Step 2

Go to Diagnostic

System Check -

Engine Controls in

Engine Controls - 6.0L

(LQ4)

1. Install a scan tool.

2. Turn ON the ignition, with the engine

OFF.

3. Record the DTC Freeze Frame and

Failure Records.

4. Clear the DTC.

5. Drive the vehicle in the D4 drive range

in second, third or fourth gear under
steady acceleration, with a TP angle at
20-99%.

While the scan tool TCC Enable is Yes, does
the scan tool display a TCC Slip Speed greater
than the specified range?

IMPORTANT:

Before clearing the DTC, use the scan
tool in order to record the Freeze
Frame and Failure Records. Using the
Clear Info function erases the Freeze
Frame and Failure Records from the
PCM.

130

RPM

Go to Step 3

Go to Intermittent

Conditions in Engine

Controls - 6.0L (LQ4)

2004 Hummer H2

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

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