DTC P18AE

Automatic Transmission - 10L80 MHS MQC | Diagnostic Information and Procedures | Document ID: 5377349 Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC P18AE Transmission Range Control Enable Valve Stuck On Diagnostic Fault Information

Note

DTC P18AE will set with a hydraulic/mechanical condition. The components are listed from the least to the most intrusive to service.

Component	DTC	Condition
Q77J Transmission Control Solenoid Valve 9	P18AE	Binding or Sticking Mechanically damaged Missing components
Line Enable Anti-Backflow Valve Valve Spring Valve Body Bore	P18AE	Binding or Sticking Debris on the component. Mechanically damaged
Control Valve Body	P18AE	Fluid/oil passage — Restricted / Leaking

Circuit/System Description For an overview of the component/system, refer to: Park - Engine Running Reverse Neutral - Engine Running Drive Range, First Gear Drive Range, Second Gear Drive Range, Third Gear Drive Range, Fourth Gear Drive Range, Fifth Gear Drive Range, Sixth Gear Drive Range, Seventh Gear Drive Range, Eighth Gear Drive Range, Ninth Gear Drive Range, Tenth Gear Electronic Component Description Conditions for Running the DTC Q77B Transmission Control Solenoid Valve 2 = Enabled Battery Voltage = Greater than 9 V Engine Speed = Greater than 499 RPM High Side Driver 1, 2 = On Ignition and Start Signal = 9 to 32 V Ignition and Start Switch Signal = On Input Shaft Speed Sensor = Greater than 300 RPM Transmission Fluid Temperature = Greater than 0°C (32°F) Transmission Service Fast Learn = Disabled Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC Gear Ratio = Incorrect Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type B DTC Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type B DTC Reference Information DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool Reference Control Module References Circuit/System Verification

1. Verify the condition does not exist: Incorrect fluid level or condition » Refer to: Transmission Fluid Level and Condition Check ⇒ If a condition exists Repair or replace as necessary ⇓ If no condition exists
2. Ignition » On / Vehicle » In Service Mode
3. Perform the following action: Clear the DTCs.
4. 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. Verify that no DTC listed in the DTC Descriptor Category is set. ⇒ If any of the DTCs are set Refer to: Diagnostic Fault Information & Verify the conditions listed in the table do not exist ⇓ If none of the DTCs are set
5. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Automatic Transmission Fluid, Fluid Pan and/or Filter Replacement Control Valve Body Replacement For control module replacement, programming, and setup refer to: Control Module References Additional Procedures Transmission Service Fast Learn Procedure — Perform only when the component/system is serviced.