Circuit Description
The PCM controls the torque converter clutch pulse width modulation
(TCC PWM) solenoid valve. The solenoid controls the hydraulic
fluid for TCC apply and release. When the TCC is fully applied, the engine
is coupled directly to the transmission through the TCC.
The TCC used is an electronically controlled capacity clutch (ECCC).
The PCM will normally allow a small amount of slip to occur with the
ECCC. When the TCC is engaged, TCC slip speed is maintained at approximately
20 to 50 RPM.
If the PCM detects high torque converter slip when the TCC is commanded
ON, then DTC P0741 sets. DTC P0741 is a type B DTC.
Conditions for Running the DTC
• | No TP sensor DTC P0121, P0122 or P0123. |
• | No VSS DTC P0502 or P0503. |
• | No AT ISS sensor DTC P0716 or P0717. |
• | No TCC stuck ON DTC P0742. |
• | No TCC PWM solenoid valve DTC P1860. |
• | No TCC release switch DTC P1887. |
• | The engine torque is greater than 28 N·m (21 lb ft). |
• | The transmission fluid temperature is 20-130°C (68-266°F). |
• | The TP angle is 4-99%. |
Conditions for Setting the DTC
The following conditions occur twice for 7 seconds during the
same ignition cycle:
• | The TCC duty cycle is 50% or greater. |
• | The TCC slip speed is greater than 180 RPM. |
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. |
• | The PCM inhibits 4th gear if the transmission is in Hot Mode. |
• | The PCM freezes transmission adaptive 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
• | Residue or contamination may cause valves to stick intermittently. |
Test Description
The number below refers to the step number on the diagnostic table.
-
This step verifies that the TCC engages
when commanded ON by the scan tool.
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 - 3.4L or
Diagnostic System Check - Engine Controls
in Engine Controls - 3.8L
|
2
| Did you perform the Transmission Fluid Checking Procedure?
| --
| Go to
Step 3
| Go to
Transmission Fluid Check
|
3
|
- Install a scan tool.
- Turn ON the ignition with the engine OFF.
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze
Frame and Failure Records for reference. Using the Clear DTC Information
function will erase the stored Freeze Frame and Failure Records from the
PCM.
- Record the Freeze Frame and Failure Records.
- Clear the DTCs.
- Drive the vehicle at 72 km/h (45 mph).
- Using the scan tool, command the TCC PWM solenoid valve ON.
- Monitor the TCC slip speed.
Does the scan tool indicate the TCC Slip Speed is within the specified value?
| -50 RPM
to +180 RPM
| Go to Diagnostic Aids
| Go to
Step 4
|
4
|
- Inspect the following components:
• | The cooling system for plugging |
• | The TCC control valve for sticking |
• | The TCC regulator valve for sticking |
• | The TCC PWM solenoid valve stuck and O-ring seal
for leaks |
• | The pressure regulator valve |
• | The TCC blowoff valve or spring for damage or not seating |
• | The TCC signal orifice in the spacer plate plugged |
• | The #1 check ball missing or leaking |
• | The spacer plate gaskets torn or leaking |
• | The turbine shaft seals for leaks |
• | The torque converter clutch |
- Repair or replace the component as necessary.
Did you complete the repair?
| --
| Go to
Step 5
| --
|
5
| Perform the following procedure in order to verify the repair:
- Select DTC.
- Select Clear DTC Information.
- Operate the vehicle under the following conditions:
• | Drive the vehicle in D3 or D4 until the TCC is engaged. |
• | The transmission fluid temperature is 20-130°C (68-266°F). |
• | TP angle must be 4-99 percent. |
• | The engine torque is greater than 28 N·m (21 lb ft). |
• | The TCC is commanded ON at greater than 50 percent duty
cycle. |
• | The TCC slip speed must be less than 50 RPM for at least
4 seconds. |
- Select Specific DTC.
- Enter DTC P0741.
Has the test run and passed?
| --
| Go to
Step 6
| Go to
Step 2
|
6
| With a 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 - 3.4L or
Diagnostic Trouble Code (DTC) List
in Engine Controls 3.8L
| System OK
|