P07F6
Gear 9 Incorrect Ratio.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 7
- AreaTransmission
- F6
- FaultThe specific fault in that area
What it means
P07F6 is a generic transmission code meaning the control unit has detected an incorrect ratio for ninth gear. It calculates the actual ratio by comparing transmission input speed with output speed, and the figure did not match the expected ninth gear ratio for long enough to set the fault. This points to slip, a hydraulic or shift control problem, or faulty speed signals.
Symptoms
- Transmission warning light or malfunction message on the dash
- Transmission slipping or revving high when in ninth gear
- Gearbox dropping out of ninth or refusing to select it
- Harsh, delayed or flared shifts into or out of ninth
- Car stuck in limp mode or restricted to a lower gear
- Poor fuel economy at cruising speed
Possible causes
- Low, degraded or contaminated transmission fluid causing clutch slip or low pressurelikely
- Faulty or erratic input or output speed sensor, or damaged sensor wiring and connectorlikely
- Worn or burnt clutch packs or brake bands applied in ninth gearpossible
- Faulty shift solenoid or valve body problem causing low or incorrect clutch apply pressurepossible
- Outdated transmission control unit software or calibration, where a manufacturer update is known for this faultpossible
- Incorrect tyre size or wheel speed signal errors skewing the ratio calculationrare
- Internal mechanical damage such as a failed gear set or torque converterrare
How to diagnose
- Read all stored codes and freeze frame data, noting gear, speed, load and fluid temperature when the fault set, and check for other transmission or speed sensor codes
- Check for relevant technical service bulletins and software updates for the specific model and gearbox
- Check the transmission fluid level and condition using the manufacturer's procedure, looking for burnt smell, dark colour or debris
- Inspect the speed sensor wiring, connectors and housings for damage, corrosion, oil ingress or metal contamination
- View live data for input speed, output speed and calculated gear ratio on a road test and compare with the specified ratio for ninth
- Check that tyre sizes match and that wheel speed signals are plausible
- Test shift solenoid operation and line or clutch pressures where the procedure allows, as the method depends on the gearbox
- Inspect the valve body and drain pan for clutch material or metal particles if slip is confirmed
How to fix
- Correct the fluid level or replace degraded fluid and filter as the manufacturer specifies
- Repair damaged wiring or connectors, or replace the faulty speed sensor
- Replace the faulty shift solenoid or repair the valve body
- Apply an available transmission control unit software update where a known fault exists
- Overhaul or replace the transmission if the clutches or gear set are worn or damaged
- Fit correct matching tyres if a size mismatch is the cause
Can I keep driving?
Medium severity
The car can usually be driven short distances, but expect limp mode or poor shifting, and have it checked soon. Continued slip can cause expensive internal damage, so avoid heavy loads and stop driving if slipping gets worse.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.