What it means
The transmission control module detected an incorrect shift from 4th gear. The code does not specify which component caused the shift error.
At a glance
- Usually lights the check-engine light
How it works
During a shift out of 4th gear, the TCM monitors the requested gear change, shift timing, and transmission speed signals. This code sets when the shift does not match the expected transition from 4th; it does not name the component that caused the error.
Common causes
Most likely first.
- Shift solenoid sticking or malfunctioning
- Low or degraded transmission fluid
- Hydraulic pressure loss or valve body fault
- Worn or damaged clutch or friction element
- 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 information and review commanded gear, actual gear, transmission speeds, and related codes to see when the shift from 4th failed.
- Check fluid level and condition using the manufacturer’s specified method, and inspect for leaks affecting hydraulic pressure.
- Inspect the transmission wiring and connectors serving the shift solenoids and speed sensors for damage, corrosion, or poor contact.
- Use live data on a safe road test to compare the commanded shift out of 4th with speed-sensor response and shift timing.
- If the electrical signals are plausible, test solenoid operation and hydraulic pressure using manufacturer procedures, then inspect for internal friction-element wear.
Common fixes
- Repair leaks and correct low fluid with the specified transmission fluid.
- Replace degraded or incorrect fluid if inspection and service guidance call for it.
- Repair damaged wiring or connectors in the solenoid and speed-sensor circuits.
- Replace a shift solenoid confirmed to stick or fail its circuit test.
- Repair a confirmed valve-body fault or worn internal friction element.
Can I keep driving?
If the shift out of 4th produces strong slipping, shuddering, or limp mode, avoid further driving because the fault can worsen internal damage. If symptoms are mild, keep driving limited and gentle, with no towing, until diagnosis.
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.