P0752
DTC P0751 or P0752
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0751
- Shift Solenoid 1 Valve Performance - Stuck Off
DTC P0752
- Shift Solenoid 1 Valve Performance - Stuck On
Circuit/System Description
The shift solenoid (SS) valve 1 is part of the control solenoid valve assembly, which has no serviceable components. The SS valve 1 is a normally closed (NC) solenoid valve and controls fluid pressure to the clutch select valve. When SS valve 1 is commanded on, fluid pressure acts on the clutch select valve, moving the valve to another position. Fluid from the R1/4-5-6 regulator valve flows though the clutch select valve and is directed to either the low and reverse clutch or the 4-5-6 clutch, depending on the position of the clutch select valve.
Conditions for Running the DTC
P0751
* DTC P0101, P0102, P0103, P0106, P0107, P0108, P0171, P0172, P0174, P0175, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0401, P042E, P0716, P0717, P0722, P0723, or P182E is not set.
* Transmission fluid temperature is -6.6°C ( 20°F) or greater.
* Engine speed is 400-7500 RPM for 5 seconds.
* Output shaft speed is 100 RPM or greater or the throttle is 0.5 percent or greater.
* Ignition voltage is 9-32 V.
* Shift is complete.
* Engine torque signal is valid.
* Throttle position signal is valid.
* High-Side driver is enabled.
P0752
* DTC P0101, P0102, P0103, P0106, P0107, P0108, P0171, P0172, P0174, P0175, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0401, P042E, P0716, P0717, P0722, P0723, or P182E is not set.
* Transmission fluid temperature is -6.6°C ( 20°F) or greater.
* Engine speed is 400-7500 RPM for 5 seconds.
* Output shaft speed is 100 RPM or greater or the throttle is 0.5 percent or greater.
* Ignition voltage is 9.0 volts or greater.
* Shift is complete.
* Throttle position signal is valid.
* High-Side driver is enabled.
Conditions for Setting the DTC
P0751
Transmission control module (TCM) detects gear slip greater than 400 RPM for 1.5 seconds with 1st gear commanded and the gear ratio is 1.37-1.52. This must occur 8 times.
P0752
TCM detects gear slip greater than 400 RPM for 1.5 seconds when 3rd gear is commanded. This must occur 5 times.
Action Taken When the DTC Sets
P0751
* DTC P0751 is a type B DTC.
* TCM inhibits 1st gear.
* TCM inhibits Neutral idle.
P0752
* DTC P0752 is a type A DTC.
* TCM limits the transmission to 2nd range and reverse.
* TCM inhibits Tap Up/Down function.
* TCM inhibits manual shifting of forward gears.
* TCM disables neutral idle.
* TCM freezes adapts.
* TCM commands maximum line pressure.
Conditions for Clearing the DTC
* DTC P0751 is a type B DTC.
* DTC P0752 is a type A DTC.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics Electrical Diagrams
Connector End View Reference
* Component Connector End Views Fuel Pump and Level Sensor Assembly
* Inline Harness Connector End Views X100
Description and Operation
* Transmission General Description Transmission General Description
* Transmission Component and System Description Transmission Component and System Description
* Electronic Component Description Electronic Component Description
* Drive Range, First Gear Engine Braking (Gen 1) Drive Range, First Gear Engine Braking (Gen 1)Drive Range, First Gear Engine Braking (Gen 2) Drive Range, First Gear Engine Braking (Gen 2)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
DT-48616 - Solenoid Assembly Test Kit & Adapter Harness
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
1. Ignition ON, engine OFF.
2. Verify DTC P0716, P0717, P0722, P0723, P077C, P077D, P07BF, or P07C0 was not set by reviewing the scan tool Freeze Frame/Failure Records data.
• If a DTC was set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If a DTC was not set
3. Engine idling at the normal operating temperature, gear selector in the Park position, with parking brake applied and drive wheels chocked.
4. Verify transmission fluid level and condition is correct. Refer to Transmission Fluid Level and Condition Check Transmission Fluid Level and Condition Check.
• If the transmission fluid level and condition is not correct
Repair as necessary.
• If the transmission fluid level and condition is correct
5. Ignition ON, clear the TCM DTCs with a scan tool.
6. From a stop, accelerate to 72 km/h (45 mph) with the throttle position greater than 15 percent. Perform this test 8 times.
7. Verify DTC P0751 or P0752 did not set.
• If a DTC sets
Refer to Circuit/System Testing.
• If a DTC does not set
8. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
9. Verify the DTC does not set.
• If a DTC sets
Refer to Circuit/System Testing.
• If a DTC does not set
10. All OK
Circuit/System Testing
Note: You must perform the Circuit/System Verification first.
1. Engine idling at the normal operating temperature.
2. Verify the transmission line pressures are within the specified range. Refer to Line Pressure Check Line Pressure Check and Solenoid Valve Pressure (Gen 1) Solenoid Valve Pressure (Gen 1).
• If the pressures are not within range
Refer to Fluid Pressure High or Low Fluid Pressure High or Low.
• If the pressures are within range
3. Ignition OFF, remove the Q8 Control Solenoid Valve Assembly.
4. Verify a pressure change occurs for all solenoids when performing the solenoid test. Refer to Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test.
• If a pressure change does not occur
Replace the Q8 Control Solenoid Valve Assembly.
• If a pressure change occurs
5. Verify the mechanical conditions listed below do not exist. Repair or replace as necessary.
P0751 - Control Valve Body
* Clutch select valve bore plug undersized. Plug should be a valve fit in the bore.
* Check ball #1 missing, damaged/malformed.
* Seat for check ball #1 damaged or leaking.
P0751 or P0752 - Control Valve Body
* Clutch select valve stuck from debris, sediment, binding, or a scored bore.
* Low and reverse and 4-5-6 clutch regulator valve stuck or sticking from debris, sediment, binding, or a scored bore.
P0751 or P0752 - Channel Plate and Spacer Plate
Oil channels or orifices blocked by debris.
P0751 or P0752 - Q8 Control Solenoid Valve Assembly
* Not pressurizing due to shift solenoid valve 1 being stuck OFF or leaking.
* Pressure not exhausting due to shift solenoid valve 1 being stuck ON.
* Control signal fluid supply leak due to valve body filter plate assembly cracked, blocked, or damaged gasket seal.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Perform the Transmission Adaptive Values Learn Transmission Adaptive Values Learn following all transmission repairs.
* Control Solenoid Valve and Transmission Control Module Assembly Replacement Service and Repair
* Control Module References Control Module References for control solenoid valve assembly replacement, programming and setup.