6T40/6T45 - Automatic Transmission

DTC P0752

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 P0752
- Shift Solenoid (SS) 1 Valve Performance - Stuck On

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. The transmission control module (TCM) looks for good shifts from first gear engine braking, to first gear freewheel, to second gear and then if third gear indicates neutral, and the TFP Sw 5 does not change states, the TCM sets the DTC.

Conditions for Running the DTC

* The commanded gear is third.
* Commanded gear has achieved first lock, first freewheel or second gear.

Conditions for Setting the DTC

The attained gear slip is 100 RPM or greater for 3 seconds or more.

Action Taken When the DTC Sets

* DTC P0752 is a Type A DTC.
* The TCM forces TCC off.
* The TCM inhibits TUTD.
* The TCM freezes adapts.

Conditions for Clearing the DIC/DTC

DTC P0752 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.

Reference Information
Schematic Reference

Drive Range, Third Gear (Drive Range, Third Gear)
Description and Operation

* Transmission General Description (Transmission General Description)
* Transmission Component and System Description (Transmission Component and System Description)

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-48616 Control Solenoid Test Plate
* DT-48616-10 Adapter Harness

Circuit/System Verification

1. Perform the Transmission Fluid Check (Transmission Fluid Check).
2. Operate the vehicle in drive from a complete stop, with the calculated throttle position greater than 15 percent to obtain 72 km/h (45 mph) 2 times. If the DTC resets, go to Circuit/System Testing.
3. Verify that the scan tool parameter matches the Shift Solenoid Valve State and Gear Ratio (6T40/6T45 - Automatic Transmission) table for each gear selected.

Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with 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 Solenoid Performance Test (Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test) to test for a stuck open or stuck closed shift solenoid valve inside of the control solenoid (w/body and TCM) valve assembly.

• If a stuck open or stuck closed valve is found, perform the Control Solenoid Valve and Transmission Control Module Assembly Cleaning (Control Solenoid Valve and Transmission Control Module Assembly Cleaning) procedure in an attempt to clean or free up a potential sticking valve of dirt or debris.

3. If the DTC resets after the cleaning procedure perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Control Solenoid Valve and Transmission Control Module Assembly Inspection).

• If the shift solenoid 1 is found to be leaking or stuck ON, replace the control solenoid (w/body and TCM) valve assembly.
• If the control solenoid (w/body and TCM) valve assembly shift solenoid functions correctly, inspect the lower control valve body assembly for the following:

* Clutch select solenoid valve and valve body bore for scratches, gouges, scuffing, scoring, and sediment.
* The valve should move freely in the bore without stopping or binding.
* Inspect clutch select valve 2 (CSV2) fluid circuits for blockage.
* Inspect the control solenoid (w/body and TCM) valve assembly filter plate for sediment or debris that could block the apply fluid flow.

Repair Instructions

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

Important: Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Control Solenoid Valve and Transmission Control Module Assembly Inspection).

* Refer to Control Module References (Programming and Relearning) for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.
* Perform the Service Fast Learn Adapts (Programming and Relearning) following all transmission related repairs.