With Powertrain Control Module
Wiring Diagram:
CIRCUIT DESCRIPTION
IMPORTANT: DTC P0741 inspects for high Torque Converter Clutch (TCC) slip in 2nd and 3rd gear only. The transmission must be in hot mode or experiencing a wide open throttle maneuver in order for the TCC to be commanded ON in 2nd and 3rd gear.
The Powertrain Control Module (PCM) energizes the Torque Converter Clutch Pulse Width Modulated Solenoid Valve (TCC PWM Sol. Valve) by grounding circuit 418. This blocks the exhaust for TCC signal fluid and allows filtered 2-3 drive fluid to feed the TCC signal circuit. When the vehicle's operating conditions are appropriate for TCC application, the PCM begins the TCC duty cycle to approximately 30%. This allows TCC signal fluid pressure to move the converter clutch shift valve into the apply position and direct regulated apply fluid to the torque converter. The PCM then increases (ramps) the duty cycle to approximately 60%, where regulated apply fluid pressure, applies the converter clutch. The vehicle application determines the TCC apply rate. Once the TCC applies, the duty cycle immediately increases to approximately 70% to achieve full apply pressure, in the regulated apply fluid circuit.
The TCC PWM Sol. Valve is de.energized by the PCM opening circuit 418. This action allows the TCC signal fluid to exhaust through the solenoid and blocks filtered 2-3 drive fluid from entering the TCC signal circuit. The loss of fluid pressure in the TCC signal circuit releases the TCC.
If the PCM detects high TCC slip when the TCC is commanded ON, then DTC P0741 sets. DTC P0741 is a type D DTC. For California emissions vehicles DTC P0741 is a type B DTC.
CONDITIONS FOR SETTING THE DTC
^ No A/T ISS Sensor DTCs P0716 or P0717.
^ No OSS DTCs P0722, or P0723.
^ No TCC Stuck ON DTC P0742.
^ No TCC PWM Sol. Valve DTC P1860.
^ No Automatic Transmission Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.) DTC P1810.
^ The TCC PWM Sol. Valve is commanded in 2nd or 3rd gear for greater than 0.6 seconds.
^ The engine must be running greater than 475 RPM for at least 7 seconds.
^ The TCC Duty Cycle is greater than 70% for 1.0 seconds.
^ The gear ratio must indicate 2nd or 3rd gear.
^ The APP angle is 15-99%.
^ The TFP Val. Position Sw. must be in D4, D3, or D2 and has not changed state within 4 seconds.
^ The TFT must be 20 to +150°C (68-302°F).
^ The TCC Slip Speed is greater than 175 RPM for 3 seconds.
^ All conditions must be met for a total of 4 occurrences.
ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) for California emissions vehicles.
^ The PCM inhibits the TCC.
^ The PCM increases line pressure.
^ The PCM inhibits 4th gear.
^ DTC P0741 is stored in PCM history.
CONDTIONS FOR CLEARING THE DTC
^ For California emissions, the PCM turns OFF the MIL after three consecutive trips without a failure reported.
^ A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm.up cycles without a failure reported.
^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.
DIAGNOSTIC AIDS
^ Residue or contamination may cause shift valves to stick intermittently.
^ First diagnose and clear any engine DTCs or APP Sensor codes that are present. Then inspect for any transmission DTCs that may have reset.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step tests for excessive TCC slip when TCC is commanded on.
3. This step inspects for possible causes of no TCC apply.