Diagnostic Instructions
DTC Descriptor
DTC P1751: Shift Valve 1 Performance
Diagnostic Fault Information
The following fault table will help determine if a hydraulic circuit or an incorrect position of a valve train component affects the transmission operation.
Component
| Cause
| DTCs
|
Automatic Transmission Fluid Pump Cover Assembly
| TCC control valve stuck in fluid pump cover assembly
| P1751
|
Control Solenoid (w/body and TCM) Valve Assembly
| Shift Solenoid 1:
| • | Always exhausting - Stuck On |
| • | Not exhausting - Stuck Off |
| • | Needle piston or armature pin binding |
| • | Control signal fluid supply leak - valve body filter plate assembly cracked or damaged gasket seal |
| • | Control valve body spacer plate assembly number 4 ball check valve orifice damaged or burred |
| P1751
|
Circuit/System Description
The shift valve 1 (clutch select valve 2) is part of the lower control valve body. The shift valve 1 (clutch select valve 2) controls fluid to the R1 and 4-5-6 clutches. During this diagnostic test, intrusive actions are taken
by the transmission control module (TCM) to test the clutch select valve 2 to see if the valve is stuck. The TCM commands the shift solenoid (SS) 1 ON to put pressure on the valve toward the spring and at the same time, elevates line pressure
slightly to assist the spring side pressure. If the spring is broken, the valve will slip back toward the spring indicating a mechanical failure and the DTC will set.
Conditions for Running the DTC
| • | No DTCs P0716 or P0717. |
| • | No DTCs P0722 or P0723. |
| • | No DTCs P2763, P2763, or P2764. |
| • | No DTCs P0741 or P0742. |
| • | The engine run time is greater than 5 seconds. |
| • | The transmission fluid temperature (TFT) is 20-130°C (68-266°F). |
| • | The calculated throttle position is between 8-90 percent. |
| • | The engine torque is greater than 50 N·m (36 lb ft). |
| • | No upshift or downshift in process. |
| • | DTC P0742 has not passed or failed for this torque converter clutch (TCC) cycle. |
| • | The attained gear slip is equal to or greater than 70 RPM. |
Conditions for Setting the DTC
The TCM detects attained gear slip greater than 75 RPM for 0.5 seconds.
Action Taken When the DTC Sets
DTC P1751 is a Type B DTC.
Conditions for Clearing the DTC
| • | DTC P1751 is a Type B DTC. |
| • | The TCM freezes transmission adaptive functions. |
Diagnostic Aids
When attempting to set transmission performance DTCs, observe the Freeze Frame and Failure Records to assist in duplicating the failure conditions. Ensure the transmission fluid level is correct and there are no leaks.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
Description and Operation
Transmission Component and System Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References
for scan tool information
Circuit/System Verification
Operate the vehicle in drive with the calculated throttle position greater than 8 percent and ensure the TCC is commanded ON and OFF a minimum of 5 times.
| ⇒ | If the DTC resets, go to Component Testing. |
Component Testing
Inspect the lower control valve body for a stuck clutch select valve 2, a broken clutch select valve 2 spring, debris or damage.
| ⇒ | If you found a valve body concern, repair or replace the lower control valve body as necessary. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
