Diagnostic Instructions
DTC Descriptor
DTC P0751: Shift Solenoid (SS) 1 Valve Performance - Stuck Off
Circuit/System Description
The shift solenoid (SS) valve 1 is part of the lower control valve body. The SS valve 1 is a normally closed (NC) solenoid valve and controls fluid to the clutch select valve 2 and related clutches. During this diagnostic test,
intrusive actions are taken by the transmission control module (TCM) to test the SS valve 1 to see if the valve is stuck OFF. When in first gear engine braking, if first gear ratio is not achieved in a predetermined period of time and the closest gear
ratio detected if fourth, the TCM commands second gear and if second gear ratio is attained this indicates a stuck OFF SS valve 1 and the DTC will set.
Conditions for Running the DTC
| • | No DTCs P0716, P0717, P0722 or P0723. |
| • | No DTCs P1915 or P1825. |
| • | First gear locked is commanded. |
| • | Commanded gear slip is equal to or less than 75 RPM for 2 seconds. |
Conditions for Setting the DTC
Fail Case 1 and Fail Case 2 must occur in sequential order.
Fail Case 1
Commanded gear equals first lock and gear box slip equals greater than 100 RPM for 3 seconds.
Fail Case 2
Commanded gear equals first lock and gear ratio equals fourth and gear box slip is between 35-100 RPM within 0.5-1.0 seconds.
Action Taken When the DTC Sets
Depending when the vehicle was manufactured, DTC P0751 is either a Type A or Type B DTC.
Conditions for Clearing the DTC
Depending when the vehicle was manufactured, DTC P0751 is either a Type A or Type B DTC.
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. |
| • | Under certain conditions where DTC P0751 sets, the TCM provides functional status to other control modules. This may result in the module disabling the cruise control. For this condition, correct the DTC and then power-down to reset the TCM. |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
DTC Type Reference
Electrical Information Reference
Special Tools Required
DT-47825
Control Solenoid Test Plate
Circuit/System Verification
- Perform the
Transmission Fluid Check
.
- Operate the vehicle in drive from a complete stop, with the calculated throttle position greater than 15 percent to obtain 56 km/h (35 mph) 2 times.
| ⇒ | If the DTC resets, go to Circuit/System Testing. |
Circuit/System Testing
- Perform the
Line Pressure Check
.
| ⇒ | If the pressure is out of specification correct that concern first. |
- Perform the
Control Solenoid Valve and Transmission Control Module Assembly Cleaning
and retest the DTC as outlined in the Circuit/System Verification steps.
| ⇒ | If the DTC resets, continue on with testing. |
- Perform the
Control Solenoid Valve and Transmission Control Module Assembly Inspection
.
| ⇒ | If a concern is found, repair or replace the control solenoid (w/body and TCM) valve assembly. |
- Perform the
Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test
.
| ⇒ | If the shift solenoid 1 is found to be leaking or stuck OFF, replace the control solenoid (w/body and TCM) valve assembly. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
- Replace the control solenoid (w/body and TCM) valve assembly. Refer to
Control Module References
for replacement, setup, or programming.
- Perform the
Service Fast Learn Adapts
.
