M99 - Automatic Transmission
DTC P0756
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 P0756
- Shift Solenoid (SS) 2 Valve Performance - Stuck Off
Circuit/System Description
The shift solenoid (SS) valve 2 is part of the control solenoid (w/body and TCM) valve assembly and is not serviced separately. The SS valve 2 is a normally closed (NC) solenoid valve and controls fluid to the hybrid low, 1-2 boost valve assembly and related clutches. During this diagnostic test, intrusive actions are taken by the transmission control module (TCM) to test the SS valve 2 to see if the valve is stuck OFF. When in EVT 1, gear 1, or gear 2, if the correct gear ratio is not achieved in a predetermined period of time, the TCM commands gear 3 and if gear 3 ratio is attained this indicates a stuck OFF SS valve 2 and the DTC will set.
Conditions for Running the DTC
Gear 3, 4, or EVT 2 is commanded.
Conditions for Setting the DTC
The TCM detects second gear ratio is achieved.
Action Taken When the DTC Sets
DTC P0756 is a Type A DTC.
Conditions for Clearing the DTC
DTC P0756 is a Type A 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
Electrical Information Reference
* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
* Scan Tool Output Controls (Scan Tool Output Controls)
* Scan Tool Data List (Scan Tool Data List)
* Scan Tool Data Definitions (Scan Tool Data Definitions)
Special Tools
DT-47825 Control Solenoid Test Plate
Circuit/System Verification
1. Perform the Transmission Fluid Check (Transmission Fluid Check) .
2. Operate the vehicle in drive 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
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 Cleaning (Control Solenoid Valve and TCM Assembly Solenoid Performance Test) and retest the DTC as outlined in the Circuit/System Verification steps.
• If the DTC resets, continue on with testing.
3. Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Control Solenoid Valve and TCM Assembly Solenoid Performance Test) .
• If a concern is found, repair or replace the control solenoid (w/body and TCM) valve assembly.
4. Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test (Control Solenoid Valve and TCM Assembly Solenoid Performance Test) .
• If the solenoid 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 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.