Gear 5 Incorrect Ratio
What it means
While fifth gear was commanded, the transmission computer found that the ratio between input and output speed does not match fifth gear. This code applies to transmissions with five or more gears, and drivers usually notice it at high highway speeds.
Symptoms4
- Engine speed rising at high speed without a matching gain in road speed.
- Sudden engine speed flare on the 4-5 shift.
- Transmission staying in fourth or repeatedly dropping out of fifth.
- Check engine light on and higher highway fuel consumption.
Possible causes5
- Low or degraded transmission fluid.
- A faulty solenoid that controls fifth gear.
- A valve body fault or a leak in the fifth gear circuit.
- Worn clutch or band that applies fifth gear, depending on design.
- Damaged internal seals for this clutch.
How to diagnose5
- Check the fluid level and condition.
- Watch input and output speed in fifth gear at steady highway cruise.
- Confirm the difference between engine speed and input speed is normal to rule out torque converter slipping.
- Read solenoid and shift codes such as P0784, and test the solenoids with a scan tool.
- Have a hydraulic pressure test done in fifth gear.
How to fix5
- Correct the fluid level, or change the fluid and filter.
- Replace the faulty solenoid.
- Repair or replace the valve body.
- Repair the clutch or band that applies fifth gear, along with its seals.
- Clear the codes and confirm steady engine speed in fifth gear on a highway road test.
Repair cost
In Saudi riyals; the highlighted part is the expected range for this fault.
The cost is low when fluid or a solenoid is the cause, and much higher when the transmission must be opened to repair the internal clutch or band.
Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026
Frequently asked questions
Does this code apply to every automatic car?
No, only to transmissions with five or more forward gears.
Why does the slipping only show on the highway?
Because fifth gear is normally used at high speeds, so its fault only shows once you reach those speeds.
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This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.
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