DTC P0741 or P0742 Hybrid
Diagnostic Instructions
DTC Descriptors
DTC P0741: Torque Converter Clutch (TCC) System - Stuck Off
DTC P0742: Torque Converter Clutch (TCC) System - Stuck On
Diagnostic Fault Information
Hydraulic Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
1-2 SS Valve
| --
| --
| --
| P0751, P0752
|
2-3 SS Valve
| --
| --
| --
| P0756, P0757
|
TCC PWM Valve
| --
| --
| --
| P0741, P0742
|
Typical Scan Tool Data
Torque Converter Clutch (TCC) System Parameter Data
Circuit
| Normal
| Short to Ground
| Open/High Resistance
| Short to Voltage
|
Operating Conditions:
Engine running, normal operating temperature
Parameter Normal Range:
OK
|
1-2 Sol. CKT Status
| OK
| Open/Short to GND
| Open/Short to GND
| Short to Volts
|
2-3 Sol. CKT Status
| OK
| Open/Short to GND
| Open/Short to GND
| Short to Volts
|
TCC Duty Cycle CKT Status
| OK
| Open/Short to GND
| Open/Short to GND
| Short to Volts
|
Circuit/System Description
The transmission control module (TCM) 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 TCM 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 20-50 RPM.
Conditions for Running the DTC
P0741
| • | No TP sensor DTCs P0121, P0122, or P0123. |
| • | No ISS DTCs P0716 or P0717. |
| • | No OSS DTCs P0722 or P0723. |
| • | No TCC system stuck ON DTC P0742. |
| • | No TCC release switch DTCs P0842 or P0843. |
| • | No TCC control circuit DTCs P2763 or P2764. |
| • | The calc. throttle position is between 8-90 percent. |
| • | The TCC PWM solenoid valve is commanded ON. |
| • | The TCC duty cycle is 65 percent or greater for 2 seconds. |
| • | The commanded gear is 1st. |
| • | The engine speed is greater than 500 RPM for 2 seconds. |
| • | The transmission fluid temperature is between 20-130°C (68-266°F). |
| • | The engine torque is greater than 50 N·m (37 lb ft). |
P0742
| • | No TCC system stuck OFF DTC P0741. |
| • | No TCC control circuit DTCs P2763 or P2764. |
| • | The calc. throttle position is between 8-90 percent. |
| • | The TCC PWM solenoid valve is commanded OFF. |
| • | The gear ratio is between 0.63:1 and 1.73:1. |
| • | The engine torque is greater than 50 N·m (37 lb ft). |
| • | The vehicle speed is 16 km/h (10 mph) or greater. |
Conditions for Setting the DTC
P0741
The TCC slip speed is 150 RPM or greater for 8 seconds 2 times during the same ignition cycle.
P0742
The TCC slip speed is between -20 and 40 RPM for 6 seconds 3 times during the same ignition cycle.
Action Taken When the DTC Sets
P0741
| • | DTC P0741 is a Type B DTC. |
| • | The TCM forces the TCC OFF. |
| • | The TCM inhibits TCC engagement. |
| • | The TCM inhibits 4th gear if the transmission is in Hot Mode. |
| • | The TCM freezes transmission adaptive functions. |
| • | The Hybrid control module (HCM) inhibits Hybrid operation. |
P0742
| • | DTC P0742 is a Type B DTC. |
| • | The TCM commands the TCC ON at maximum capacity. |
| • | The TCM commands maximum line pressure. |
| • | The TCM freezes transmission adaptive functions. |
| • | The TCM forces the TCC ON. |
| • | The Hybrid control module (HCM) inhibits Hybrid operation. |
Conditions for Clearing the DTC
DTCs P0741 and P0742 are Type B DTCs.
Diagnostic Aids
If the DTC is cleared, then will not reset when the vehicle is driven, some of the following conditions may exist:
| • | Restricted fluid circuits |
| • | Inspect transmission fluid lines to radiator. Lines may be pinched, plugged or twisted. |
| • | Internal damage to the torque converter may prevent TCC application. |
| • | It is possible for an internal TCM failure which may not allow sufficient current to operate the solenoids. Verify TCM functionality by commanding the suspected solenoid ON/OFF using the scan tool and listen for a click. |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Perform the
Transmission Fluid Check to verify correct fluid level and condition. The transmission fluid level should be within the crosshatch band and the transmission fluid should be red or dark brown.
- Operate the vehicle at 72 km/h (45 mph) with the throttle position at 20 percent. Command the TCC ON with a scan tool while observing the scan tool TCC Slip Speed parameter. The reading should be below 175 RPM.
| ⇒ | If the TCC Slip Speed is greater than 175 RPM for greater than 5 seconds, inspect for the following conditions and repair/replace as necessary: |
| • | TCC PWM solenoid valve mechanically stuck OFF leaking |
| • | TCC regulator apply valve stuck in the OFF position |
| • | TCC Sol valve stuck in the OFF position or leaking |
| • | TCC enable valve stuck in the OFF position |
| • | Misaligned damaged or leaking valve body gasket |
| • | Inspect the forward clutch input housing assembly for the input shaft fluid seal ring leaking or worn |
| ⇒ | If the TCC Slip Speed is between 150-1,500 RPM for greater than 5 seconds, inspect for the following conditions and repair/replace as necessary: |
| • | Clogged exhaust orifice in the TCC solenoid valve |
| • | Converter clutch apply valve stuck in the apply position |
| • | Misaligned or damaged valve body gasket |
| • | Restricted release passage |
| • | Restricted transmission cooler line |
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the repair.
DTC P0741 or P0742 Non-Hybrid
Diagnostic Instructions
DTC Descriptors
DTC P0741: Torque Converter Clutch (TCC) System - Stuck Off
DTC P0742: Torque Converter Clutch (TCC) System - Stuck On
Diagnostic Fault Information
Hydraulic Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
1-2 SS Valve
| --
| --
| --
| P0751, P0752
|
2-3 SS Valve
| --
| --
| --
| P0756, P0757
|
TCC PWM Valve
| --
| --
| --
| P0741, P0742
|
Typical Scan Tool Data
Torque Converter Clutch (TCC) System Parameter Data
Circuit
| Normal
| Short to Ground
| Open/High Resistance
| Short to Voltage
|
Operating Conditions:
Engine running, normal operating temperature
Parameter Normal Range:
OK
|
1-2 Sol. CKT Status
| OK
| Open/Short to GND
| Open/Short to GND
| Short to Volts
|
2-3 Sol. CKT Status
| OK
| Open/Short to GND
| Open/Short to GND
| Short to Volts
|
TCC Duty Cycle CKT Status
| OK
| Open/Short to GND
| Open/Short to GND
| Short to Volts
|
Circuit/System Description
The transmission control module (TCM) 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 TCM 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 20-50 RPM.
Conditions for Running the DTC
P0741
| • | No TP sensor DTCs P0121, P0122, or P0123. |
| • | No ISS DTCs P0716 or P0717. |
| • | No OSS DTCs P0722 or P0723. |
| • | No TCC system stuck ON DTC P0742. |
| • | No TCC release switch DTCs P0842 or P0843. |
| • | No TCC control circuit DTCs P2763 or P2764. |
| • | The calc. throttle position is between 8-90 percent. |
| • | The TCC PWM solenoid valve is commanded ON. |
| • | The TCC duty cycle is 65 percent or greater for 2 seconds. |
| • | The commanded gear is 1st. |
| • | The engine speed is greater than 500 RPM for 2 seconds. |
| • | The transmission fluid temperature is between 20-130°C (68-266°F). |
| • | The engine torque is greater than 50 N·m (37 lb ft). |
P0742
| • | No TP sensor DTCs P0121, P0122, or P0123. |
| • | No ISS DTCs P0716 or P0717. |
| • | No OSS DTCs P0722 or P0723. |
| • | No TCC system stuck OFF DTC P0741. |
| • | No TCC control circuit DTCs P2763 or P2764. |
| • | The calc. throttle position is between 8-90 percent. |
| • | The TCC PWM solenoid valve is commanded OFF. |
| • | The gear ratio is between 0.63:1 and 1.73:1. |
| • | The engine torque is greater than 50 N·m (37 lb ft). |
| • | The vehicle speed is 16 km/h (10 mph) or greater. |
| • | The engine speed is greater than 500 RPM for 2 seconds. |
| • | The transmission fluid temperature is between 20-130°C (68-266°F). |
Conditions for Setting the DTC
P0741
The TCC slip speed is 150 RPM or greater for 8 seconds 2 times during the same ignition cycle.
P0742
The TCC slip speed is between -20 and 40 RPM for 6 seconds 3 times during the same ignition cycle.
Action Taken When the DTC Sets
P0741
| • | DTC P0741 is a Type B DTC. |
| • | The TCM forces the TCC OFF. |
| • | The TCM inhibits TCC engagement. |
| • | The TCM inhibits 4th gear if the transmission is in Hot Mode. |
| • | The TCM freezes transmission adaptive functions. |
P0742
| • | DTC P0742 is a Type B DTC. |
| • | The TCM forces the TCC ON. |
| • | The TCM commands the TCC ON at maximum capacity. |
| • | The TCM commands maximum line pressure. |
| • | The TCM freezes transmission adaptive functions. |
Conditions for Clearing the DTC
DTCs P0741 and P0742 are Type B DTCs.
Diagnostic Aids
If the DTC is cleared, then will not reset when the vehicle is driven, some of the following conditions may exist:
| • | Restricted fluid circuits |
| • | Inspect transmission fluid lines to radiator. Lines may be pinched, plugged or twisted. |
| • | Internal damage to the torque converter may prevent TCC application. |
| • | It is possible for an internal TCM failure which may not allow sufficient current to operate the solenoids. Verify TCM functionality by commanding the suspected solenoid ON/OFF using the scan tool and listen for a click. |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Perform the
Transmission Fluid Check to verify correct fluid level and condition. The transmission fluid level should be within the crosshatch band and the transmission fluid should be red or dark brown.
- Operate the vehicle at 72 km/h (45 mph) with the throttle position at 20 percent. Command the TCC ON with a scan tool while observing the scan tool TCC Slip Speed parameter. The reading should be below 175 RPM.
| ⇒ | If the TCC Slip Speed is greater than 175 RPM for greater than 5 seconds, inspect for the following conditions and repair/replace as necessary: |
| • | TCC PWM solenoid valve mechanically stuck OFF leaking |
| • | TCC regulator apply valve stuck in the OFF position |
| • | TCC Sol valve stuck in the OFF position or leaking |
| • | TCC enable valve stuck in the OFF position |
| • | Misaligned damaged or leaking valve body gasket |
| • | Inspect the forward clutch input housing assembly for the input shaft fluid seal ring leaking or worn |
| ⇒ | If the TCC Slip Speed is between 150-1,500 RPM for greater than 5 seconds, inspect for the following conditions and repair/replace as necessary: |
| • | Clogged exhaust orifice in the TCC solenoid valve |
| • | Converter clutch apply valve stuck in the apply position |
| • | Misaligned or damaged valve body gasket |
| • | Restricted release passage |
| • | Restricted transmission cooler line |
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the repair.
