How the system works
Follow energy, material, information, and mechanical force through the system before focusing on a single component.
A high-level system map. Component roles and exact circuit behavior vary by vehicle.
- 01InputInput torque enters
- 02Flow 2A ratio or drive state is selected
- 03Flow 3Hydraulic or electronic controls apply the change
- 04Flow 4Torque leaves through the driveline
- 05Protect / verifyLubrication and cooling protect the assembly
Follow the sequence, stop when evidence changes the path, and verify the exact vehicle information before acting.
- 01Input torque enters
- 02A ratio or drive state is selected
- 03Hydraulic or electronic controls apply the change
- 04Torque leaves through the driveline
- 05Lubrication and cooling protect the assembly
Major components in context
Create and hold operating ratios
System contextDirects hydraulic or electromechanical action
System contextReport input, output, and driver request
System contextLubricate, cool, clean, and transmit force where applicable
System contextSupport the assembly and carry output torque
System contextSymptom patterns and first direction
Slipping or flare
Reduce load and document gear, temperature, speed, and commanded state.
Follow the diagnostic path →SYMPTOMHarsh or delayed engagement
Separate control, supply, engine, mount, and internal hydraulic possibilities.
Follow the diagnostic path →SYMPTOMNo movement or warning
Do not continue applying throttle; check state, leaks, codes, and driveline connection.
Follow the diagnostic path →A system-level diagnostic method
Record gear, temperature, speed, load, and timing
Use the result to support or reject a cause group before moving to a more invasive test.
Scan engine, transmission, brake, and driveline modules
Use the result to support or reject a cause group before moving to a more invasive test.
Inspect for leaks, damage, and correct external control
Use the result to support or reject a cause group before moving to a more invasive test.
Verify fluid only with the exact procedure
Use the result to support or reject a cause group before moving to a more invasive test.
Compare commanded and actual operation before internal conclusions
Use the result to support or reject a cause group before moving to a more invasive test.
Evidence worth preserving
Codes, freeze-frame, and shift history
Commanded versus actual gear or ratio
Fluid condition checked correctly
Noise, vibration, or movement location
Use the VIN, installed equipment, current manufacturer information, and applicable safety rules.
Safety and professional boundary
Unexpected movement and hot-fluid warning
Secure the vehicle, keep clear of rotating driveline parts, and use approved support. Transmission fluid and cases can be hot, and incorrect level procedures can be hazardous.