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DTC P0741 TCC System Stuck Off
|NOTE |
|Applicable vehicles: |
|Grand Prix (VIN W) |
DTC P0741 TCC System Stuck Off
|[pic] |
| |
|Click to Enlarge |
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 the electronically controlled capacity clutch (ECCC). The ECCC allows the TCC to slip a small amount without excessive wear. This allows smooth application and release of the TCC. When the TCC PWM solenoid valve engages the TCC, TCC slip speed is maintained at approximately 20 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 DTCs P0121, P0122 or P0123 are set.
• No VSS DTCs P0502 or P0503 are set.
• No A/T ISS sensor DTCs P0716 or P0717 are set.
• No TCC stuck ON DTC P0742 is set.
• No TFP manual valve position switch DTC P1810 is set.
• No TCC PWM solenoid valve DTC P1860 is set.
• No TCC release switch DTC P1887 is set.
• The transmission gear range is D4, D3 or D2.
• The time since the last gear range change is greater than 3 seconds.
• The transmission fluid temperature is greater than 20°C (68°F).
• The engine speed is greater than 500 RPM for 5 seconds and not in fuel shut off.
• The TP angle is 4-35%.
• The TCC PWM solenoid valve is commanded ON for more than 0.5 seconds.
• The TCC is at maximum apply pressure.
Conditions for Setting the DTC
The TCC slip speed is greater than 180 RPM twice for 7 seconds each.
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 shift adapts.
• The PCM stores DTC P0741 in PCM history.
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 clears the DTC from the PCM history.
• The PCM clears the DTC from the PCM history if the vehicle completes 40 consecutive warm-up cycles without an emission related diagnostic fault occurring.
• The PCM cancels the DTC default actions when the fault no longer exists and 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.
5. This step verifies that the TCC engages when commanded ON by the scan tool.
DTC P0741 TCC System -- Stuck Off
|Step |Action |Value(s) |Yes |No |
|1 |Was the Powertrain On-Board Diagnostic (OBD) System Check |-- |Go to Step 2 |Go to Powertrain On Board|
| |performed? | | |Diagnostic (OBD) System |
| | | | |Check in Engine Controls |
|2 |Was the transmission fluid checking procedure performed? |-- |Go to Step 3 |Go to Transmission Fluid |
| | | | |Check |
|3 |Install the Scan Tool . |-- |Go to Step 5 |Go to Step 4 |
| |Start the engine. | | | |
| |WARNING | | | |
| | | | | |
| |Important: Before clearing the DTCs, use the scan tool in | | | |
| |order to record the Freeze Frame and Failure Records for | | | |
| |reference. Using the Clear Info function will erase the stored| | | |
| |Freeze Frame and Failure Records from the PCM. | | | |
| | | | | |
| |Record the Freeze Frame and Failure Records. | | | |
| |Clear the DTCs. | | | |
| |Monitor TCC release pressure on the scan tool. | | | |
| |Is TCC release pressure present? | | | |
|4 |Inspect the following components: |-- |Go to Step 7 |-- |
| |Refer to Unit Repair. | | | |
| |The TCC control valve | | | |
| |The TCC regulator apply valve | | | |
| |The TCC PWM solenoid valve | | | |
| |The pressure regulator valve | | | |
| |Repair or replace any malfunctioning components. | | | |
| |Is the inspection or repair complete? | | | |
|5 |Drive the vehicle at above 72 km/h (45 mph) with a TP angle of|-50 RPM to +50|Go to Diagnostic |Go to Step 6 |
| |less than 30%. |RPM |Aids | |
| |Using the scan tool, command the TCC PWM solenoid valve ON and| | | |
| |monitor the TCC slip speed display. | | | |
| |Is the slip speed within the specified value? | | | |
|6 |Inspect the following components: |-- |Go to Step 7 |-- |
| |Refer to Unit Repair. | | | |
| |The TCC control valve | | | |
| |The TCC regulator valve | | | |
| |The TCC PWM solenoid valve | | | |
| |The turbine shaft seals | | | |
| |The torque converter clutch | | | |
| |Repair or replace any malfunctioning components. | | | |
| |Is the inspection or repair complete? | | | |
|7 |Perform the following procedure in order to verify the repair:|-- |System OK |Go to Step 1 |
| |Select DTC. | | | |
| |Select Clear Info. | | | |
| |Road test the vehicle in D4. | | | |
| |Monitor TP angle and TCC slip speed on the scan tool. Ensure | | | |
| |that the TP angle is 4-35% and that the TCC slip speed is less| | | |
| |than 50 RPM for at least 4 seconds when the TCC is commanded | | | |
| |ON at maximum capacity. | | | |
| |Select Specific DTC. | | | |
| |Enter DTC P0741. | | | |
| |Has the test run and passed? | | | |
DTC P0751 1-2 Shift Solenoid Valve Performance
|NOTE |
|Applicable vehicles: |
|Grand Prix (VIN W) |
DTC P0751 1-2 Shift Solenoid Valve Performance
|[pic] |
| |
|Click to Enlarge |
Circuit Description
The 1-2 shift solenoid valve controls the fluid acting on the 1-2 and 3-4 shift valves. The PCM commands the solenoid ON or OFF by controlling the ground on the circuit. When the solenoid is OFF, the line pressure exhausts through the solenoid valve, allowing the 1-2 shift valve to be held by spring pressure in the second and third gear position. When the solenoid is ON, the exhaust flow is blocked, allowing line pressure to the 1-2 shift valve. This moves the 1-2 shift valve to the first and fourth gear position.
When the PCM detects a 1-1-4-4 or a 2-2-3-3 shift pattern under the test conditions, without an electrical malfunction, then DTC P0751 sets. DTC P0751 is a type A DTC.
Conditions for Running the DTC
• No TP DTCs P0122 or P0123.
• No VSS DTC(s) P0502 or P0503.
• No TCC enable solenoid electrical DTC P0740.
• No TCC stuck ON DTC P0742.
• No 1-2 solenoid electrical DTC P0753.
• No 2-3 solenoid electrical DTC P0758.
• No TCC PWM solenoid electrical DTC P1860.
• The engine speed is greater than 500 RPM for 5 seconds.
• Not in fuel shut off.
• The transmission range switch indicates D4.
• The vehicle speed is greater than 8 km/h (5 mph).
• The transmission temperature is 20-130°C (68-266°F).
• The traction control is not active.
Conditions for Setting the DTC
DTC P0757 will set if either fail-cases 1,2,3 and 4 or 1,2,3 and 5 are true 3 times.
Failure Criteria
Case 1
• 1-2 shift is commanded.
• The throttle position is 18-55% and is constant within 3%.
• The vehicle speed is 8-64 km/h (5-40 mph).
• 2nd gear is commanded and, within 2.0 seconds, the engine speed is 100 RPM greater than the engine speed of the commanded 1st gear.
Case 2
• 2-3 shift is commanded.
• The throttle position is 10-55% and is constant within 10%.
• The vehicle speed is 32-89 km/h (20-55 mph).
• 3rd gear is commanded and, within 2.5 seconds, the engine speed is 130 RPM less than the engine speed of the commanded 2nd gear.
Case 3
• 3-4 shift is commanded.
• The throttle position is 5-40% and is constant within 7%.
• The vehicle speed is 56-121 km/h (35-75 mph).
• 4th gear is commanded and, within 1.0 second, the engine speed is 1 RPM greater than the engine speed of the commanded 3rd gear.
Case 4
• Fourth gear is commanded and the TCC is ON.
• The throttle position is 2-30%.
• The speed ratio is 0.97-1.18.
• The TCC slip is 500-1,000 RPM for more than 3 seconds.
Case 5
• Fourth gear is commanded and the TCC is ON.
• The throttle position is 2-30%.
• The speed ratio is 0.68-0.82.
• The TCC slip is 0 to +50 RPM for more than 3.0 seconds.
Action Taken When the DTC Sets
• The PCM illuminates the malfunction indicator lamp (MIL).
• The PCM inhibits downshifts to 2nd gear if the vehicle speed is greater than 48 km/h (30 mph).
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 clears the DTC from PCM history.
• The PCM clears the DTC from the PCM history if the vehicle completes 40 consecutive warm-up cycles without an emission related diagnostic fault occurring.
• 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
• Perform the transmission fluid checking procedure as requested in the table. Inspect the transmission fluid for color, sediment and debris.
• Ensure that the scan tool commanded gear has correct solenoid states and ratio. Refer to Shift Solenoid Valve State and Gear Ratio table.
Test Description
The number below refers to the step numbers on the diagnostic table.
2. The Transmission Fluid Checking Procedure will examine the fluid for color, sediment and debris.
3. Verify the DTC, and inspect shift solenoid and shift valve for sediment, debris or damage.
4. If the problem is not corrected in step 3, replace the 1-2 shift solenoid.
DTC P0751 1-2 Shift Solenoid Performance
|Step |Action |Value(s) |Yes |No |
|1 |Was the Powertrain On-Board Diagnostic (OBD) System Check performed?|-- |Go to Step |Go to Powertrain On Board |
| | | |2 |Diagnostic (OBD) System |
| | | | |Check |
|2 |Perform the transmission fluid checking procedure. Refer to |-- |Go to Step |Go to Transmission Fluid |
| |Transmission Fluid Check . | |3 |Check |
| |Did you perform the transmission fluid checking procedure? | | | |
|3 |Install the Scan Tool . |-- |Go to Step |Go to Diagnostic Aids |
| |With the engine OFF, turn the ignition switch to the RUN position. | |4 | |
| |WARNING | | | |
| | | | | |
| |Important: Before clearing the DTCs, 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. | | | |
| | | | | |
| |Record the Freeze Frame and Failure Records. | | | |
| |Clear the DTC. | | | |
| |Drive the vehicle in D4 range, under the following: | | | |
| |Accelerate the vehicle, ensuring that the PCM commands 1st, 2nd, 3rd| | | |
| |and 4th gear | | | |
| |Did you detect a 1-1-4-4 or 2-2-3-3 shift pattern? | | | |
|4 |Inspect for the following conditions: |-- |Go to Step |Go to Step 5 |
| |Shift solenoid screens 374 in the control valve body spacer plate | |6 | |
| |assembly for sediment or debris. | | | |
| |1-2 shift solenoid valve for a damaged or missing O-ring or cracked | | | |
| |housing. | | | |
| |1-2 shift valve sticking due to sediment, debris or damage. | | | |
| |Refer to Unit Repair. | | | |
| |Was a condition found and corrected? | | | |
|5 |Replace the 1-2 shift solenoid. |-- |Go to Step |-- |
| |Refer to 1-2 Shift Solenoid Valve Replacement . | |6 | |
| |Is the replacement complete? | | | |
|6 |Perform the following in order to verify the repair: |-- |System OK |Go to Step 1 |
| |Select DTC. | | | |
| |Select Clear Info. | | | |
| |Operate the vehicle under the following conditions: | | | |
| |The traction control is not active. | | | |
| |The transmission fluid temperature is 20-130°C (68-266°F) | | | |
| |The engine speed is more than 500 RPM for 5 seconds. | | | |
| |The vehicle is not in fuel shut off. | | | |
| |The gear range is D4. | | | |
| |The vehicle speed is more than 8 km/h (5 mph). | | | |
| |All the conditions in the following pass cases must be met: | | | |
| |Case 1 | | | |
| |The PCM commands a 1-2 shift. | | | |
| |The throttle position is 18-55% and constant within + or - 3%. | | | |
| |The vehicle speed is 8-64 km/h (5-40 mph). | | | |
| |Within 2 seconds, the engine speed in 2nd gear must be 130 RPM less | | | |
| |than the last engine speed in 1st gear. | | | |
| |Case 2 | | | |
| |The PCM commands a 2-3 shift. | | | |
| |The throttle position is 10-55% and constant within + or - 10%. | | | |
| |The vehicle speed is 32-89 km/h (20-55 mph). | | | |
| |Within 2.5 seconds, the engine speed in 3rd gear must be 130 RPM | | | |
| |less than the last engine speed in 2nd gear. | | | |
| |Case 3 | | | |
| |The PCM commands a 3-4 shift. | | | |
| |The throttle position is 5-40% and constant within + or - 7%. | | | |
| |The vehicle speed is 56-121 km/h (35-75 mph). | | | |
| |Within 1.0 second, the engine speed in 4th gear must be 250 RPM less| | | |
| |than the last engine speed in 3rd gear. | | | |
| |Case 4 | | | |
| |The PCM commands 4th gear. | | | |
| |The TCC is commanded ON. | | | |
| |The throttle position is 2-30%. | | | |
| |The speed ratio is 0.68-0.82. | | | |
| |The TCC slip speed is 0-50 RPM for more than 3 seconds. | | | |
| |Select Specific DTC. | | | |
| |Enter DTC P0751. | | | |
| |Has the test run and passed? | | | |
DTC P0742 TCC System Stuck On
|NOTE |
|Applicable vehicles: |
|Grand Prix (VIN W) |
DTC P0742 TCC System Stuck On
|[pic] |
| |
|Click to Enlarge |
Circuit Description
The torque converter clutch (TCC) solenoid valve is an ON/OFF (normally OFF) valve which controls the converter clutch apply and release. The torque converter clutch pulse width modulation (TCC PWM) solenoid valve works with the TCC solenoid valve to control the clutch apply rate (feel). The PCM controls the duty cycle on the TCC PWM solenoid valve to regulate the feed pressure to the converter clutch regulator valve, which in turn, regulates the converter clutch apply pressure.
When the TCC solenoid valve is OFF, TCC fluid is exhausted through the solenoid. The converter clutch apply valve is held by the converter clutch spring and line pressure. In this position, converter feed pressure enters the release passage to release the clutch. The apply fluid bypasses the apply valve to the cooler passage.
When the TCC solenoid valve is ON, fluid an not exhaust through the solenoid. This allows TCC signal fluid pressure to move the converter clutch apply valve against spring force and line pressure. When shifted, the apply valve:
• Directs regulated apply pressure from the converter clutch regulator valve into the apply passage which applies the clutch
• Allows converter feed fluid to exhaust
• Directs converter feed fluid into the cooler passage
When the TCC is applied, the clutch is nearly locked-up to the converter cover. This vehicle is equipped with an electronically controlled capacity clutch (ECCC) which controls TCC slip speed between -20 to +50 RPM to avoid noise, vibration and chuggle with TCC apply.
If the PCM detects 3 occurrences of TCC slip between -20 and +50 RPM for 5 seconds, when the TCC is commanded OFF, then DTC P0742 sets. DTC P0742 is a type B DTC.
Conditions for Running the DTC
• No TP DTCs P0122 or P0123.
• No VSS DTCs P0502 or P0503.
• No TCC PWM solenoid electrical DTC P1860.
• No TCC enable solenoid electrical DTC P0740.
• Not in fuel shut off.
• The engine speed is more than 500 RPM for 5 seconds.
• The commanded gear is not 1st.
• The transmission gear indicates 2nd, 3rd or 4th.
• The throttle angle is 14-50%.
• The engine torque is 95-271 N·m (70-200 lb ft).
• The engine speed is 800-4,000 RPM.
• The vehicle speed is 32-112 km/h (20-70 mph).
• The speed ratio is 0.65-1.4.
• The last gear range selector positon change occurred more than 3 seconds ago.
• The PCM has commanded the TCC OFF.
Conditions for Setting the DTC
DTC P0742 sets when, under the conditions for running the DTC, the TCC slip speed is -20 to +50 RPM, 3 times for 5 seconds each.
Action Taken When the DTC Sets
The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the conditions exist for setting the DTC.
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 clears the DTC from PCM history.
• The PCM clears the DTC from the PCM history if the vehicle completes 40 consecutive warm-up cycles without an emission related diagnostic fault occurring.
• 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
• An engine stalling symptom may be present when a drive gear is engaged.
• Inspect the transmission fluid and filter for sediment or debris.
Test Description
The number below refers to the step number on the diagnostic table.
2. A TCC slip speed in the range shown indicates that this DTC is current.
DTC P0742 Torque Converter Clutch System Stuck ON
|Step |Action |Value(s) |Yes |No |
|1 |Was the Powertrain On-Board Diagnostic (OBD) System Check performed? |-- |Go to Step |Go to Powertrain On |
| | | |2 |Board Diagnostic (OBD) |
| | | | |System Check |
|2 |Install the Scan Tool . |-20 to +50 RPM|Go to Step |Go to Diagnostic Aids |
| |With the engine OFF, turn the ignition switch to the RUN position. | |3 | |
| |WARNING | | | |
| | | | | |
| |Important: Before clearing the DTCs, 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. | | | |
| | | | | |
| |Record the Freeze Frame and Failure Records. | | | |
| |Then Clear the DTC. | | | |
| |Start and run the vehicle. | | | |
| |Select TCC Slip Speed on the scan tool. | | | |
| |With the transmission in D4, drive the vehicle through the 1-2 | | | |
| |upshift. | | | |
| |In second gear is the TCC Slip Speed within the range specified? | | | |
|3 |Perform the transmission fluid checking procedure. Refer to |-- |Go to Step |-- |
| |Transmission Fluid Check . | |4 | |
| |Inspect for the following conditions: | | | |
| |The orificed TCC filter is damaged or missing from the channel. | | | |
| |The TCC apply valve stuck ON because of sediment or damage. | | | |
| |The TCC solenoid valve stuck ON because of sediment or damage. | | | |
| |Refer to Control Valve Body Inspection in Unit Repair. | | | |
| |Was a condition found and corrected? | | | |
|4 |Perform the following in order to verify the repair: |-- |System OK |Go to |
| |Select DTC. | | | |
| |Select Clear Info. | | | |
| |Operate the vehicle under the following conditions: | | | |
| |The gear range is D2, D3 or D4. | | | |
| |The commanded gear is not 1st. | | | |
| |The engine speed is greater than 500 RPM for 5 seconds. | | | |
| |Not in fuel shut off. | | | |
| |The engine torque is 95-270 N·m (70-200 lb ft). | | | |
| |The throttle position is 14-50%. | | | |
| |The engine speed is 800-4,000 RPM. | | | |
| |The vehicle speed is 32-112 km/h (20-70 mph). | | | |
| |The speed ratio is 0.65-1.18. | | | |
| |The last gear change occurred more than 3 seconds ago. | | | |
| |The PCM commands the TCC OFF. | | | |
| |The TCC slip speed is 150-2,000 RPM for 4 seconds. | | | |
| |Select Specific DTC. | | | |
| |Enter DTC P0742. | | | |
| |Has the test run and passed? | | | |
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