Diagnostic Instructions
DTC Descriptors
DTC P0751 : 1-2 Shift Solenoid (SS) Valve Performance - No First, Fourth or Fifth Gear
DTC P0752: 1-2 Shift Solenoid (SS) Valve Performance - No Second or Third Gear
Circuit/System Description
The 1-2 shift solenoid (SS) valve is a normally-closed exhaust valve that, in conjunction with the 2-3 shift solenoid (SS) valve, allows 4 different shifting combinations. The 1-2 SS valve is
attached to the control valve body, within the transmission.
Conditions for Running the DTC
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 P182A, P182C, P182D, P182E, P182F 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). |
P0752
| • | 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 P182A, P182C, P182D, P182E, P182F 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 greater than 10 percent. |
| • | The input shaft speed is 200-6,800 RPM. |
| • | The output shaft speed is greater than 100 RPM. |
| • | The engine torque is greater than 32 N·m (24 lb ft). |
Conditions for Setting the DTC
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. |
P0752
Both of the following conditions must occur twice during the same trip:
| • | The TCM commands 2nd gear and the resulting gear ratio is 3.33:1-3.50:1 for 2 seconds. |
| • | The TCM commands 3rd gear and the resulting gear ratio is 0.98:1-1.03:1 for 3 seconds. |
Action Taken When the DTC Sets
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. |
P0752
| • | DTC P0752 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. |
| • | The TCM inhibits 3-2 downshifts if the vehicle speed is greater than 8 km/h (5 mph). |
Conditions for Clearing the DTC
DTCs P0751 and P0752 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 |
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
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Transmission Control Module 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 in Drive and ensure that the TCM commands all gears. The ratios should match the commanded gear for all gears. Refer to
Shift Solenoid Valve State and Gear Ratio.
- 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.
Circuit/System Testing
Using the scan tool, clear the DTC. If DTC is set, drive the vehicle in D5 and ensure that the TCM commands all gears with a throttle angle of 10 percent or greater. 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: |
| • | The 1-2 shift solenoid valve O-ring worn or damaged. |
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.
| ⇒ | If the resistance is not within the specified range, replace the affected solenoid. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the repair.
