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2004 Pontiac Grand Am

Transmission problem
2004 Pontiac Grand Am 4 cyl Front Wheel Drive Automatic 61000 miles

PO741 Torque Converter Clutch Circuit Performance or Stuck Off
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Lorenza
April 18, 2009.



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 powertrain control module (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 MAF DTCs P0101, P0102 or P0103 - 3.4L.  No MAP DTCs P0106, P0107 or P0108 - 2.2L.  No MAP DTCs P0107 or P0108 - 3.4L.  No TP DTCs P0121, P0122 or P0123.  No VSS DTCs P0502 or P0503.  No ISS DTCs P0716 or P0717.  No TCC stuck ON DTC P0742.  No TFP manual valve position switch DTC P1810.  No TCC electrical DTC P1860.  No TCC release switch DTC P1887.  The transmission fluid temperature is 20-130 ° C (68-266 ° F).  The commanded gear is 2nd, 3rd or 4th.  The TP is greater than 8 percent.  The PCM commands the TCC Duty Cycle 60% or more for greater than 3 seconds.  The engine torque is greater than 41 N.m (30 lb ft). Conditions for Setting the DTC The TCC slip speed is greater than 200 RPM for 6 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 adaptive functions.  The PCM inhibits 4th gear when in HOT mode.  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. 2: This step inspects the transmission fluid to ensure that it is at the proper level. 3: This step verifies that the TCC engages when commanded ON by the scan tool. DTC P0741 (2.2L & 3.4L) Step Action Value(s) Yes No 1 Did you perform the Diagnostic System Check - Engine Controls? - Go to Diagnostic System Check - Engine Controls in Engine Controls -2.2L or Diagnostic System Check - Engine Go to Step 2 Controls in Engine Controls - 3.4L 2 Did you perform the Transmission Fluid Checking Procedure? - Go to Step 3 Go to Transmission Fluid Checking Procedure 3 1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. Record the DTC Freeze Frame and Failure Records. 4. Clear the DTC. 5. Drive the vehicle at 72 km/h (45 mph). 6. Using the scan tool, command the TCC PWM solenoid valve ON. 7. Monitor the TCC slip speed. Is the slip speed less than the specified value? 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. 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 (2.2L) or DTC P1860 (3.4L) Go to Step 5 1. Inspect for the following conditions:  The TCC PWM solenoid valve O-ring for leaks or cuts  The TCC PWM solenoid valve for the filter being clogged 5  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 Refer to Control Valve Body Disassemble in Transmission Unit Repair article.  The turbine shaft seals for leaks or cuts Refer to Drive, Driven Sprockets and Drive Link Disassemble in Unit Repair. 2. Repair any of the above conditions as necessary. 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:  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. 4. Select Specific DTC. 5. Enter DTC P0741. - Has the test run and passed? Go to Step 7 Go to Step 2 7 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 - 2.2L or Diagnostic Trouble Code (DTC) List in Engine Controls - 3.4L System OK
Check fluid level and filter, cloud be clogged!


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Merlin2021
Apr 18, 2009.