Hummer H2. Manual - part 2426

3

The TCC is hydraulically or mechanically 
stuck OFF. Inspect for the following 
conditions: 

z

Inspect the TCC PWM valve for a 
damaged exhaust orifice.  

z

Inspect for the converter apply valve 
being stuck in the OFF, release, 
position.  

z

Inspect for a misaligned or damaged 
valve body gasket.  

z

Inspect for a restricted apply valve 
passage.  

z

Inspect the torque converter clutch for 
being mechanically stuck OFF.  

 
Refer to Symptoms - Automatic 
Transmission NO TCC apply. 
Was the condition found?

-

Go to Step 4

-

4

Perform the following procedure in order to 
verify the repair: 

1. Select DTC.  

2. Select Clear Info.  

3. Drive the vehicle in D4 under the 

following conditions: 

Hold the throttle at 20-99% and 
accelerate to 88 km/h (55 mph). Ensure 
that the scan tool TCC Slip Speed is less 
than 50 RPM for 5 seconds, with the 
TCC ON. 

4. Select Specific DTC.  

5. Enter DTC P0741.  

 
Has the test run and passed?

-

Go to Step 5

Go to Step 2

5

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

 

DTC P0742 

Fig. 12: 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 valve 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 fluid 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 low TCC slip speed when the TCC is commanded OFF, then DTC P0742 sets. DTC 
P0742 is a type B DTC. 

 

2004 Hummer H2 

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

 

Conditions for Running the DTC 

z

No TP sensor DTCs P0122 or P0123.  

z

No VSS assembly DTCs P0502 or P0503.  

z

No TCC solenoid valve DTC P0740.  

z

No TFP manual valve position switch DTC P1810.  

z

No TCC PWM solenoid valve DTC P2761.  

z

The TP angle is 17-45 percent.  

z

The engine speed is greater than 450 RPM for 6 seconds.  

z

The engine is not in fuel cutoff.  

z

The TFT is between 20-130°C (68-266°F).  

z

The engine torque is 68-542 N.m (50-400 lb ft).  

z

The engine speed is 1,000-3,000 RPM.  

z

The speed ratio is 0.64 to 1.35.  

z

The vehicle speed is 24-80 km/h (15-50 mph).  

z

The gear range does not change within 5 seconds.  

z

The commanded gear is not 1st.  

z

The gear range is D4.  

z

The TCC is commanded OFF.  

Conditions for Setting the DTC 

DTC P0742 sets if the following condition occurs twice. 

The TCC slip speed is -20 to +20 RPM for 5 seconds. 

Action Taken When the DTC Sets 

z

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

z

The PCM inhibits 4th gear in Hot Mode.  

z

The PCM freezes transmission adapt functions.  

z

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.  

z

The PCM stores DTC P0742 in PCM history during the second consecutive trip in which the Conditions 
for Setting the DTC are met.  

Conditions for Clearing the MIL/DTC 

z

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

z

A scan tool can clear the MIL/DTC.  

 

2004 Hummer H2 

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

 

z

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

z

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

Diagnostic Aids 

The TCC fluid hydraulically applies the TCC, possibly causing an engine stall, under the following conditions: 

z

The TCC is hydraulically stuck ON  

z

The parking brake is applied  

z

Any gear range is selected  

Test Description 

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

2: This step tests the hydraulic state of the TCC. When the PCM commands the TCC solenoid valve OFF, 
the slip speed should increase.  

DTC P0742 

Step

Action

Value

(s)

Yes

No

1

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)

2

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 

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.

-20 to 

+20 

RPM

 

2004 Hummer H2 

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