Circuit/System Description
WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
For an overview of the component/system, refer to:
- Park - Engine Running (Mechanical Powerflow) , or Park - Engine Running (Hydraulic Circuits)
- Reverse (Mechanical Powerflow) , or Reverse (Hydraulic Circuits)
- Neutral - Engine Running (Mechanical Powerflow) , or Neutral - Engine Running (Hydraulic Circuits)
- Drive Range, First Gear (Mechanical Powerflow) , or Drive Range, First Gear (Hydraulic Circuits)
- Drive Range, Second Gear (Mechanical Powerflow) , or Drive Range, Second Gear (Hydraulic Circuits)
- Drive Range, Third Gear (Mechanical Powerflow) , or Drive Range, Third Gear (Hydraulic Circuits)
- Drive Range, Fourth Gear (Mechanical Powerflow) , or Drive Range, Fourth Gear (Hydraulic Circuits)
- Drive Range, Fifth Gear (Mechanical Powerflow) , or Drive Range, Fifth Gear (Hydraulic Circuits)
- Drive Range, Sixth Gear (Mechanical Powerflow) , or Drive Range, Sixth Gear (Hydraulic Circuits)
- Drive Range, Seventh Gear (Mechanical Powerflow) , or Drive Range, Seventh Gear (Hydraulic Circuits)
- Drive Range, Eighth Gear (Mechanical Powerflow) , or Drive Range, Eighth Gear (Hydraulic Circuits)
- Drive Range, Ninth Gear (Mechanical Powerflow) , or Drive Range, Ninth Gear (Hydraulic Circuits)
- Drive Range, Tenth Gear (Mechanical Powerflow) , or Drive Range, Tenth Gear (Hydraulic Circuits)
- Electronic Component Description
The Park Servo Valve is held out of park by fluid pressure or the M123 Transmission Park Valve Lock Solenoid Actuator.
In neutral, there is not enough fluid pressure to hold the park servo valve out of park. The park servo valve is held out of the park position when the pin on the M123 is extended, holding the park servo valve.
If the B316 Transmission Park Valve Position Switch detects the park position when in neutral, DTC P18A8 will set.