GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 Safari - 2WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 DTC P0741

Object Number: 42275 Size: MF
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

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
    • No TCC DTC P0742.
    • No VSS assembly DTCs P0502 or P0503.
    • No TCC solenoid valve DTC P0740.
    • No TFP manual valve position switch DTC P2761.
    • 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 commands maximum line pressure.
    • The PCM commands TCC off.
    • The PCM inhibits fourth gear in hot mode.
    • The PCM freezes shift adapts from being updated.
    • 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 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.

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

    2.

  2. This step inspects for possible causes of no TCC apply.

DTC P0741

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

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.

    3. 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.

  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?

130 RPM

Go to Step 3

Go to Intermittent Conditions in Engine Controls

3

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

    • Inspect the TCC PWM valve for a damaged exhaust orifice.
    • Inspect for the converter apply valve being stuck in the OFF, release, position.
    • Inspect for a misaligned or damaged valve body gasket.
    • Inspect for a restricted apply valve passage.
    • 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:

    4. 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

System OK