2010 Cadillac CTS Sedan AWD V6-3.0L Page 1631
P0742
DTC P0741 or P0742
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0741
- Torque Converter Clutch (TCC) - Stuck Off
DTC P0742
- Torque Converter Clutch (TCC) - Stuck On
Circuit/System Description
The torque converter clutch (TCC) pressure control (PC) solenoid is part of the control solenoid valve assembly which has no serviceable parts.
The TCC PC solenoid is a normally low pressure control solenoid. The TCC PC solenoid regulates transmission fluid to the TCC regulator valve in
the lower valve body and the TCC control valve in the pump cover. When vehicle operating conditions are appropriate to apply the converter
clutch, the transmission control module (TCM) will increase TCC PC current flow (duty cycle) to the TCC solenoid. The TCC PC solenoid directs
fluid pressure to move the TCC control valve to the apply position, and moves the TCC regulator apply valve to the regulating position. The TCC
regulator valve regulates TCC apply fluid pressure proportional to TCC solenoid pressure. When the TCC is fully applied, the engine is coupled
directly to the transmission. TCC release is accomplished by the TCM decreasing current flow to the TCC PC solenoid. This results in decreasing
the apply pressure which allows the TCC control valve to move to the release position. The TCM calculates torque converter slip speed based on
engine speed and transmission input shaft speed.
Conditions for Running the DTC
P0741
* DTCs P0101, P0102, P0103, P0121, P0122, P0123, P0716, P0717, P0722, P0723, P0742, P2762, P2763, or P2764 are not set.
* Ignition voltage is 8.6 volts or greater.
* The engine run time is greater than 5 seconds.
* The transmission fluid temperature (TFT) is 20-130掳C (68-266掳F).
* The accelerator pedal position signal is valid.
* The throttle position is greater than 8 percent.
* The TCM must receive a valid torque signal from the ECM.
* The engine torque is greater than 50 Nm (36 lb ft).
* The TCC is commanded ON and PWM duty cycle is greater than 60 percent for 5 seconds.
* The following 6L80/6L90 gear ratios are achieved in the specified gear range while the TCC is commanded On:
- The 2nd gear ratio is between 2.19-2.52.
- The 3rd gear ratio is between 1.42-1.63.
- The 4th gear ratio is between 1.07-1.23.
- The 5th gear is between 0.79-0.91.
- The 6th gear is between 0.62-0.71.
* The following 6L50 gear ratios are achieved in the specified gear range while the TCC is commanded On:
- The 2nd gear ratio is between 2.20-2.53.
- The 3rd gear ratio is between 1.44-1.65.
- The 4th gear ratio is between 1.07-1.23.
- The 5th gear is between 0.79-0.91.
- The 6th gear is between 0.62-0.72.
P0742
* DTCs P0101, P0102, P0103, P0121, P0122, P0123, P0716, P0717, P0722, P0723, P0741, P0742, P1751, P2762, P2763, or P2764 are not
set.
* DTC P0742 has not passed this key ON.
* Ignition voltage is between 8.6-18.0 volts.
* The engine run time is greater than 5 seconds.
* The transmission fluid temperature (TFT) is 20-130掳C (68-266掳F).
