P0734: Gear 4 Incorrect Ratio
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Drive gently to a shop - avoid motorway speeds if the fault appears in overdrive.
Symptoms
- Slipping at cruising speed
- Engine speed rising without acceleration
- Transmission dropping out of overdrive
Likely causes, most common first
- Fluid low or degraded
- Overdrive clutch pack worn
- Solenoid or valve body fault
- Torque converter clutch problem
Read P0734 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P0734 concerns fourth gear, which on most automatics is overdrive - the ratio used at motorway speed. Slip there generates heat quickly because it happens at sustained high speed rather than in brief shifts.
That makes this the ratio code least suited to being ignored until convenient. Heat degrades the fluid, degraded fluid slips more, and the cycle accelerates. If the fault appears only at cruise, staying off the motorway until it is repaired genuinely reduces the eventual bill.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning P0734
“Transmission intermittently struggling to reach 3rd, 4th, 5th gears. Performed IDS diag at shop, found hitorical code P0734 for "Incorrect gear 4 ratio" TSB 26-2046 to overhaul transmission.”2020 Ford Transit · Apr 2026
“2021 Ford Ranger with 10R80 transmission showing following codes P0733 P0734 90,000 miles on truck. jerky and slipping gear change between 3-4 and 5-6 occasionally no drive. have service records showing my truck was maintained properly.”2021 Ford Ranger · Jul 2025
“While driving my car started skipping from first to second gear and then lowering acceleration. When at a complete stop car would not accelerate and just revs through first and second gear making a pinging clicking sound. Brought to dealership to be told codes p0702 and code p0734 were reading. I've had the car one year and has been maintained. Before I got the diagnosis I drove to the dealership there was no lights on even though there was the issue and then right as I pulled in the transmission light check came on. This problem has been confirmed by Ford dealership from transmission and engine diagnostic. Not being able to accelerate at a green light put my safety at risk.”2016 Ford Focus · Jan 2025
Show 7 more owner reports
“Sudden loss of forward gears. Failure happened on highway at highway speeds. Had to carefully maneuver the truck off the road. Failure in both towing and unloaded operation. Truck will not shift in or out of drive (1-4) but reverse is still functional. Diagnostic trouble code P0731-00 and P0734 "Gear 1 and 4 Shift Incorrect Ratio". Both the dealer and RAM confirm this transmission failure. RAM has realeased a TSB which covers this failure but hasn't released a recall.”2022 Ram 3500 · Apr 2024
“Transmission FAIL check engine light went on. Car was not accellorating, bucking can't drive over 30 MGH. Thank god I was drving a back street when it happened and not the Mass Pike. Two estimates done. They both said replace the transmission. WHAT ??? Burnt transmission fluid at 77,400 miles. Three Diagnostic Errors P0128 P0734 P1790 . I have to REPLACE my transmission at a cost of $5,000 This is not supppose to happen at 77,400 . Please advise and recall or concessions available.”2014 Chrysler 200 · Feb 2023
“Tl* the contact owns a 2004 jeep liberty. The contact stated that while driving approximately 40-50 mph, the vehicle failed to shift into gears correctly. The contact stated that the rpm surged while driving 40-50 mph. The contact stated that the vehicle jerked during the failure with the check engine warning light illuminated. The contact stated that occasionally the transmission ceased in first gear. The vehicle was diagnosed by her son who retrieved dtc codes: p0700 (tcm) and p0734 (incorrect gear ratio). The vehicle was not repaired. Neither the dealer nor the manufacturer were notified of the failure. The failure mileage was approximately 100,000.”2004 Jeep Liberty · Sep 2020 · 100,000 mi
“The passenger side airbag cover are inflated , crack , bubble, look like the airbag may exploted.. I call vw and they say is it normal and not sale the part. 2009 mini van. .?? I really not think they change or overheating.. Getting words .. And yesterday from not wear the routan not drive over 35 mph when my wife driving on the highway and check engine came , 4 code ,p0733,p0734, p0792. And almost a truck hit my wife.. I look on vw forums and it is common problem,, why this it not a recall with so many people complaining and problems.. Unsafe to drive.”2009 Volkswagen Routan · Jul 2020 · 80,000 mi
“When decelerating from over 45 mph engine light comes on shifts suddenly to 3rd or 2nd gear. Codes p0733 p0734 p0792. Clear engine codes, drives normal until deceleration at elevated speeds. Transmission shifts normally otherwise. This is the 62te 6-speed transmission.”2011 Chrysler Town And Country · Jun 2019 · 83,000 mi
“I have 2008 mercury marnier 1st gear starts off fine 2nd gear won't shift till it gets to 3750 rpm then shifts 3rd fine not in 4th it's giving me codes p0732 and p0734”2008 Mercury Mariner · Oct 2017 · 140,000 mi
“Check engine light is on and I tested it with my car and it showed 2 codes p0792 (intermediate shaft speed sensor a circuit range/performance) and p0734 (gear 4 incorrect ratio). We have also been told that the brakes need replacing and it only has 47,668 miles on the vehicle. *tr”2011 Chrysler Town And Country · Jul 2013 · 47,668 mi
Cars that report P0734 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P0734?
Drive gently to a shop - avoid motorway speeds if the fault appears in overdrive.
How much does it cost to fix P0734?
Typical US repair costs range from $200 for the simplest fix (fluid and filter service) to $5,000 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P0734. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.