What it means
The transmission control system detected that the transmission is stuck in a gear, without identifying a specific gear. The code does not establish that multiple components failed.
At a glance
- Usually lights the check-engine light
How it works
The transmission control system monitors gear changes and whether the transmission reaches the requested gear. This code sets when the system detects that the transmission is stuck in a gear but does not identify which gear or prove that more than one component has failed.
Common causes
Most likely first.
- Shift solenoid sticking or malfunctioning
- Low or degraded transmission fluid
- Hydraulic pressure or valve body fault
- Shift actuator or linkage fault
- Internal transmission wear or damage
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Record freeze-frame data and scan all transmission modules for related codes, noting the commanded gear and the gear reported when the fault occurred.
- Check fluid level and condition using the vehicle maker’s specified procedure, since low or degraded fluid can affect multiple shifts.
- Inspect transmission wiring, connectors, and accessible external linkage or actuator parts for damage, loose connections, or binding.
- Use live data during a suitable test to identify which gear is being held and whether the commanded gear changes.
- Test the relevant shift solenoid or actuator circuits based on the gear and related codes, following the manufacturer’s diagnostic procedure.
- If electrical controls pass, check hydraulic pressure and valve-body operation, then assess internal transmission components as indicated.
Common fixes
- Correct low fluid or service degraded fluid using the specified procedure.
- Repair damaged wiring or connectors affecting shift control.
- Repair a confirmed binding linkage or faulty external actuator.
- Replace a shift solenoid only when testing identifies it as faulty.
- Repair a verified valve-body or internal transmission fault.
Can I keep driving?
Avoid driving if the transmission remains in one gear and cannot respond safely to traffic, especially if acceleration or low-speed control is limited. Stop safely and arrange recovery if it slips, loses drive, or shifts unpredictably.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.