P0734: Gear 4 Incorrect Ratio
5 vehicles · 5 makes
P0734 is an OBD-II diagnostic trouble code meaning “Gear 4 Incorrect Ratio.” The transmission is not achieving the correct gear ratio in 4th gear. This code appears across 5 vehicle models from 5 manufacturers.
Common Causes
Diagnostic Tools
To diagnose P0734, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (5)
FAQ
What does P0734 mean?
P0734 stands for "Gear 4 Incorrect Ratio." The transmission is not achieving the correct gear ratio in 4th gear.
What are the most common causes of P0734?
The most common causes of P0734 are: Worn clutch pack, Valve body malfunction, Low fluid pressure, Failed accumulator, Internal seal leak. The specific cause varies by vehicle.
How much does it cost to fix P0734?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P0734?
Au7o has documented P0734 across 5 vehicle models from 5 manufacturers: BMW, Chrysler, GMC, Hyundai, Kia.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.