GM Service Manual Online
For 1990-2009 cars only

Object Number: 204476  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 pulse width modulation (PWM) solenoid. When vehicle operating conditions are appropriate for TCC application, the PCM begins the TCC duty cycle at approximately 42 percent. The PCM then increases the duty cycle up to 90 percent, in order to achieve full TCC-apply pressure.

When the TCC PWM solenoid valve is de-energized, the solenoid blocks filtered 2-3 drive fluid, and allows TCC signal fluid to exhaust. When energized, the solenoid modulates fluid into the TCC signal fluid circuit. When fully energized, modulation stops, and the solenoid blocks both 2-3 drive fluid and TCC signal fluid exhaust.

When the PCM detects a high TCC slip speed when the TCC is commanded ON, then DTC P0741 sets. DTC P0741 is a type B DTC.

Conditions for Running the DTC

    • No TP DTCs P0121, P0122 or P0123.
    • No VSS DTCs P0502 or P0503.
    • No TCC stuck ON DTC P0742.
    • No TFP manual valve position switch DTC P1810.
    • No TCC release switch DTC P1887.
    • The time since the gear select lever change is greater than 6 seconds.
    • The transmission fluid temperature is 21-130°C (70-266°F).
    • The TFP manual valve position switch indicates D2, D3, or D4.
    • The commanded gear is 2nd, 3rd or 4th.
    • The TP is 8-75 percent.
    • The PCM commands the TCC ON for greater than 3 seconds.

Conditions for Setting the DTC

The TCC slip speed is greater than 250 RPM for 8 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 inhibits TCC engagement.
    • The PCM freezes transmission adapt functions.
    • 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

    • Inspect the transmission fluid level.
    • The transmission may be in hot mode. Inspect the transmission fluid lines to the radiator. The lines may be pinched, plugged or twisted.

Test Description

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

  1. This step inspects the transmission fluid to ensure that it is at the proper level.

  2. This step verifies that the TCC engages when commanded ON by the Scan Tool .

DTC P0741

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls (2.2 L) or Diagnostic System Check - Engine Controls (2.4 L) in Engine Controls

2

Did you perform the Transmission Fluid Checking Procedure?

--

Go to Step 3

Go to Transmission Fluid Check

3

  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.

  4. Record the DTC Freeze Frame and Failure Records.
  5. Clear the DTC.
  6. Drive the vehicle at 72 km/h (45 mph).
  7. Using the Scan Tool , command the TCC PWM solenoid valve ON.
  8. Monitor the TCC slip speed.

Is the slip speed less than the specified value?

50 RPM

Go to Diagnostic Aids

Go to Step 4

4

  1. Drive the vehicle at 72 km/h (45 mph).
  2. Using the Scan Tool , command the TCC PWM solenoid valve ON.
  3. Monitor the TCC Duty Cycle Short to Volts parameter.

Does the TCC Duty Cycle Short to Volts parameter indicate a short to voltage when the TCC is commanded ON?

--

Go to Step 8 of DTC P1860

Go to Step 5

5

  1. Inspect for the following conditions:
  2. • The TCC PWM solenoid valve O-ring for leaks or cuts.
    • The TCC PWM solenoid valve for the filter being clogged.
    • The TCC control valve for being stuck in the TCC release position.
    • The TCC regulated apply valve for being stuck in the TCC release position.
    • The TCC feed limit valve for being stuck due to sediment or binding.
    • The pressure regulator valve for being stuck due to sediment or binding.
    • The TCC fluid circuits for leaks.
    • The turbine shaft seals for leaks or cuts.
  3. Repair any of the above conditions as necessary.

Refer to Transmission Overhaul in Transmission Unit Repair Manual.

Did you complete the repair?

--

Go to Step 6

--

6

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
  4. • Drive the vehicle in D4 with the TP greater than 8%.
    • Obtain 72 km/h (45 mph).
    • With the TCC commanded ON and engaged, the slip speed must be less than 50 RPM for 4 seconds.
  5. Select Specific DTC.
  6. Enter DTC P0741.

Has the test run and passed?

--

System OK

Go to Step 1