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 P0751: Shift Solenoid (SS) 1 Valve Performance - Stuck OffDiagnostic Fault Information
The following fault table will help determine if a hydraulic circuit or an incorrect position or application of a component affects the transmission operation.
Component | Cause | DTCs | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Lower Control Valve Body | Clutch select valve 2 stuck - debris, sediment, binding or scored bore | P0751 | ||||||||
Control Solenoid (w/body and TCM) Valve Assembly | Clutch Pressure Control Solenoid 2:
| P0751 |
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 3- 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
| • | First gear locked is commanded. |
| • | Commanded gear slip is equal to or less than 75 RPM for 0.125 seconds. |
Conditions for Setting the DTC
The TCM detects second gear ratio is achieved.
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 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
Drive Range, First Gear Engine Braking
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
Special Tools
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 .
- Perform the Control Solenoid Valve and Transmission Control Module Assembly Cleaning and retest the DTC as outlined in the Circuit/System Verification steps.
- Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .
- Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test .
| ⇒ | If the pressure is out of specification correct that concern first. |
| ⇒ | If the DTC resets, continue on with testing. |
| ⇒ | If a concern is found, repair or replace the control solenoid (w/body and TCM) valve assembly. |
| ⇒ | 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 . |
