Automatic Transmission - 2MT70

DTC P0751

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptor
DTC P0751
- Shift Solenoid (SS) 1 Valve Performance - Stuck Off

Circuit/System Description

The shift solenoid (SS) 1 is part of the control solenoid (w/body and transmission control module (TCM) valve assembly and is not serviced separately. The control solenoid (w/body and TCM) valve assembly supplies 12 volts to SS 1 on the high side driver 1 circuit. The control solenoid (w/body and TCM) valve assembly controls the normally closed SS 1 on the SS 1 control circuit. The SS 1 controls the transmission fluid to the following valves and related clutches:

* 1-3 reverse clutch regulator
* Shift solenoid valve mode - A
* Variable high and 2-3-4 clutch regulator

Conditions for Running the DTC

Shift solenoid valve 1 is OFF when commanded ON.

Conditions for Setting the DTC

The TCM detects shift solenoid valve 1 is OFF when commanded ON.

Action Taken When the DTC Sets

* P0751 is a Type B DTC.
* The TCM pulses the solenoid in an attempt to free it.

Conditions for Clearing the DTC

P0751 is a 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.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information.
Special Tools

DT-47825 - Control Solenoid Test Plate Kit

Circuit/System Verification

1. Verify that DTCs P0721, P0722, P0723, P0966, P0967, P0969, P0970, P0971, P0973, P0974, P0976, P0977, P2720, P2721, P2728, P2729, or P2730 are not set.

• If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions).

2. Perform the Transmission Fluid Check (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.

• If the transmission fluid is low or discolored, refer to Transmission Fluid Replacement (Removal and Replacement).

3. Engine idling at operating temperature. Attempt to clean or free up a potential sticking valve with the scan tool Service Cleaning Procedure. Refer to Control Solenoid Valve and Transmission Control Module Assembly Cleaning (Control Solenoid Valve and Transmission Control Module Assembly Cleaning) for further instructions.
4. Operate the vehicle in drive from a complete stop to obtain 56 km/h (35 mph), stop the vehicle, turn the ignition Off for at least 30 seconds. Perform this 2 times.

• If the DTC resets, refer to Circuit/System Testing.

Circuit/System Testing

1. Perform the Line Pressure Check (Line Pressure Check).

• If the pressure is out of specification correct that concern first.

2. Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (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.

3. Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test (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.

• If the control solenoid (w/body and TCM) valve assembly tests normal, inspect the valve body and hydraulic circuits for a leak or a stuck valve.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Perform the Control Valve Lower Body and Upper Body Replacement (2MT70 - Automatic Transmission) for valve body repair or replacement.
* Control Module References (Programming and Relearning) for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.