GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2008 🢒 G8 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0741, P0751, P0756, or P0761

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0741 : Torque Converter Clutch (TCC) System - Stuck Off

DTC P0751: 1-2 Shift Solenoid (SS) Valve Performance - No First, Fourth or Fifth Gear

DTC P0756: 2-3 Shift Solenoid (SS) Valve Performance - No First or Second Gear

DTC P0761: 4-5 Shift Solenoid (SS) Valve Performance - No Fourth Gear

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 to 50 RPM. The 1-2 shift solenoid (SS) valve, 2-3 SS valve and the 4-5 SS valve are supplied with fused ignition voltage. The ground path is controlled by the TCM. When the TCM commands the solenoid OFF, a ground path is not provided and the filtered line pressure that is fed to the solenoid is exhausted. When the TCM commands the solenoid ON, a ground path is provided and the exhaust port is blocked, stopping the exhaust of line pressure. The TCM identifies a 1-2 SS valve, 2-3 SS valve or a 4-5 SS valve condition by monitoring the commanded gear versus gear ratio. Refer to Shift Solenoid Valve State and Gear Ratio .

Conditions for Running the DTC

P0741

    • No TP sensor DTC P0120.
    • No ISS DTCs P0716 or P0717.
    • No OSS DTCs P0722 or P0723.
    • No TCC stuck ON DTC P0742.
    • No IMS DTCs P1820, P1822, P1823, P1825, P1826 or P1915.
    • No engine torque signal circuit DTC P2637.
    • No TCC solenoid electrical DTCs P2763 or P2764.
    • The engine run time is greater than 5 seconds.
    • The IMS range is D2, D3, D4, or D5.
    • The elapsed time since the most recent range change is 6 seconds.
    • The transmission fluid temperature is 20-130°C (68-266°F).
    • The engine torque is greater than 55 N·m (41 lb ft).
    • The throttle position is 10-90 percent.
    • The gear ratio is within the following ranges:
       - 1.56:1 to 1.64:1 - 3rd gear
       - 0.98:1 to 1.03:1 - 4th gear
       - 0.73:1 to 0.77:1 - 5th gear
    • The TCC pressure is at least 200 kPa (29 psi) for 2 seconds or more.
    • The TCC duty cycle is at least 80 percent for 2 seconds or more.

P0751

    • No TP sensor DTC P0120.
    • No ISS DTCs P0716 or P0717.
    • No OSS DTCs P0722 or P0723.
    • No TCC stuck ON DTC P0742.
    • No shift solenoid electrical DTCs P0973, P0974, P0976, P0977, P0979, or P0980.
    • No IMS DTCs P1820, P1822, P1823, P1825, P1826 or P1915.
    • No engine torque delivered signal DTC P2637.
    • The engine run time is greater than 5 seconds.
    • The IMS range is not PARK, NEUTRAL or REVERSE.
    • The transmission fluid temperature is 20-130°C (68-266°F).
    • The throttle position is 10 percent or more.
    • The input shaft speed is 200-6,800 RPM.
    • The output shaft speed is 100 RPM or more.
    • The engine torque is greater than 36 N·m (26.5 lb ft).

P0756

    • No TP sensor DTC P0120.
    • No ISS DTCs P0716 or P0717.
    • No OSS DTCs P0722 or P0723.
    • No TCC stuck ON DTC P0742.
    • No shift solenoid electrical DTCs P0973, P0974, P0976, P0977, P0979, or P0980.
    • No IMS DTCs P1820, P1822, P1823, P1825, P1826 or P1915.
    • No engine torque delivered signal DTC P2637.
    • The engine run time is greater than 5 seconds.
    • The IMS range is not PARK, NEUTRAL or REVERSE.
    • The transmission fluid temperature is 20-130°C (68-266°F).
    • The throttle position is 10 percent or more.
    • The input shaft speed is 200-6,800 RPM.
    • The output shaft speed is 200 RPM or more.
    • The engine torque is greater than 36 N·m (26.5 lb ft).

P0761

    • No TP sensor DTC P0120.
    • No ISS DTCs P0716 or P0717.
    • No OSS DTCs P0722 or P0723.
    • No TCC stuck ON DTC P0742.
    • No shift solenoid electrical DTCs P0973, P0974, P0976, P0977, P0979, or P0980.
    • No IMS DTCs P1820, P1822, P1823, P1825, P1826 or P1915.
    • No engine torque delivered signal DTC P2637.
    • The engine run time is greater than 5 seconds.
    • The IMS range is not PARK, NEUTRAL or REVERSE.
    • The transmission fluid temperature is 20-130°C (68-266°F).
    • The throttle position is 10 percent or more.
    • The input shaft speed is 200-6,800 RPM.
    • The output shaft speed is 100 RPM or more.
    • The engine torque is greater than 36 N·m (26.5 lb ft).

Conditions for Setting the DTC

P0741

The TCM commands the TCC ON, and the TCC slip is between 150-250 RPM for greater than 8 seconds, 2 times during the same ignition.

P0751

Both of the following conditions must occur twice during the same trip:

    • The TCM commands 1st gear when the engine torque is greater than 40 N·m (30 lb ft) and the resulting gear ratio is 2.16:1-2.27:1 for 1.25 seconds.
    • The TCM commands 4th or 5th gear when the engine torque is greater than 36 N·m (27 lb ft) and the resulting gear ratio is 1.56:1-1.64:1 for 5 seconds.

P0756

Both of the following conditions must occur 3 times during the same trip:

    • The TCM commands 1st gear when the engine torque is greater than 40 N·m (30 lb ft) and the resulting gear ratio is 0.73:1-0.77:1 for 1.2 seconds.
    • The TCM commands 2nd gear when the engine torque is greater than 36 N·m (27 lb ft) and the resulting gear ratio is 1.56:1-1.64:1 for 1.2 seconds.

P0761

The TCM commands 4th gear and the resulting gear ratio is 0.73:1-0.77:1 for 4 seconds twice during the same trip.

Action Taken When the DTC Sets

P0741

    • DTC P0741 is a Type B DTC.
    • The TCM inhibits 5th gear if the transmission is in Hot Mode.
    • The TCM commands TCC OFF.
    • The TCM freezes transmission adaptive functions.

P0751

    • DTC P0751 is a Type B DTC.
    • The TCM commands maximum line pressure.
    • The TCM freezes transmission adaptive functions.
    • The TCM inhibits Autograde braking.
    • The TCM inhibits TAP shift operation.

P0756

    • DTC P0756 is a Type B DTC.
    • The TCM commands maximum line pressure.
    • The TCM freezes transmission adaptive functions.
    • The TCM commands HSD1 OFF.
    • The TCM inhibits Powertrain braking.
    • The TCM inhibits TAP shift operation.

P0761

    • DTC P0761 is a Type B DTC.
    • The TCM commands maximum line pressure.
    • The TCM freezes transmission adaptive functions.
    • The TCM inhibits Autograde braking.
    • The TCM inhibits Powertrain braking.
    • The TCM inhibits TAP shift operation.

Conditions for Clearing the DTC

DTCs P0741, P0751, P0756 and P0761 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:

    • Fluid contamination
    • Plugged fluid circuits
    • Restricted fluid circuits
    • Inspect transmission fluid lines to radiator. Lines may be pinched, plugged or twisted.
    • Refer to Shift Solenoid Valve State and Gear Ratio .

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Transmission General Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Transmission Control Module Scan Tool Information

Circuit/System Testing
  1. Perform the Transmission Fluid Check .
    2. ⇒Correct the transmission fluid level if the fluid is not at the proper level.
  2. Using the scan tool, clear the DTC. If DTC P0741 was set, operate the vehicle in D5 at 72 km/h (45 mph) and use the scan tool to command the TCC ON. Observe the TCC Slip Speed parameter on the scan tool. The TCC Slip Speed should be between -20 to 75 RPM.
    3. ⇒If the TCC Slip Speed is between 150-250 RPM for greater than 8 seconds, inspect the following components and repair or replace as necessary:
    • The cooling system for plugging--the cooling lines may be pinched. Refer to Transmission Fluid Cooler Flushing and Flow Test .
    • Inspect the front control valve body assembly for the TCC PWM solenoid valve sticking or leaking. Also inspect the TCC regulator apply valve for sticking. Refer to Torque Converter Clutch Solenoid Replacement .
    • Inspect the rear control valve body assembly for the control valve body ball check valve #2 stuck or missing. Refer to Control Valve Body Accumulator Assembly Replacement .
    • Inspect the fluid pump assembly for the TCC control valve stuck in the OFF position. Also inspect the TCC enable valve stuck in the OFF position. Refer to Transmission Fluid Pump Disassemble and Transmission Fluid Pump Assemble .
    • Inspect the forward clutch input housing assembly for the input shaft fluid seal ring leaking or worn. Refer to Forward and Coast Clutch Disassemble .
  3. Using the scan tool, clear the DTC. If DTC P0751, P0756 or P0761 is set, drive the vehicle in D5 and ensure that the TCM commands 1st, 2nd, 3rd, and 4th gears. The ratios should match the commanded gear for all gears. Refer to Shift Solenoid Valve State and Gear Ratio .
⇒If the gear ratios do not match the commanded gear, inspect the following and repair or replace as necessary:

P0751

    • The 1-2 shift solenoid valve mechanically stuck ON. Refer to Shift Solenoid Leak Test .
    • The 1-2 shift valve O-ring worn or damaged.
    • The 1-2 shift valve in the released position. Refer to 1-2 Shift Solenoid Valve Replacement .

P0756

    • The 2-3 shift solenoid valve mechanically stuck OFF. Refer to Shift Solenoid Leak Test .
    • The 2-3 shift valve O-ring worn or damaged.
    • The 2-3 shift valve in the applied position. Refer to 2-3 Shift Solenoid Valve Replacement .

P0761

    • The 4-5 shift solenoid valve mechanically stuck OFF. Refer to Shift Solenoid Leak Test .
    • The 4-5 shift valve O-ring worn or damaged.
    • The 4-5 shift valve in the applied position. Refer to 4-5 Shift Solenoid Valve Replacement .

Component Testing

Disconnect the wiring harness connector from the affected solenoid. Measure the resistance for the affected solenoid. The resistance should be between 15-20.3 ohms for the 1-2 SS, 2-3 SS and the 4-5 SS. The resistance should be between 10-13.6 ohms for the TCC PWM solenoid.

⇒If the resistance is not within the specified range, replace the affected solenoid.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

    • Allow the transmission to operate through all gears and all the TCC to engage. Ensure that the gear ratios match each commanded gear and the TCC slip speed is less than 75 RPM when the TCC is commanded ON.
    •  Shift Solenoid Leak Test
    •  1-2 Shift Solenoid Valve Replacement
    •  2-3 Shift Solenoid Valve Replacement
    •  4-5 Shift Solenoid Valve Replacement
    •  Torque Converter Clutch Solenoid Replacement
    •  Control Valve Body Accumulator Assembly Replacement
    •  Forward and Coast Clutch Disassemble