P0732: Gear 3 Incorrect Ratio
29 vehicles · 13 makes · $100-$12,000 repair
Most Reported On
P0732 is an OBD-II diagnostic trouble code meaning “Gear 3 Incorrect Ratio.” This code means the transmission control module detected that the gear ratio in 3rd gear does not match what it expects when the transmission is commanded into that gear. The computer compares input (turbine) speed to output shaft speed; if the math for 3rd gear is wrong, it sets this code. It usually points to internal slipping or a hydraulic/electronic control fault rather than a sensor reading error. This code is most commonly reported on 2005-2014 Mercedes-Benz CLS-Class (CLS350, CLS500, CLS550, CLS63 AMG), 2017-2023 Mercedes-Benz GLS (GLS450, GLS580), and 2016-2023 Mercedes-Benz Metris (Cargo, Passenger), plus 26 other vehicles, with repair costs ranging from $100 to $12,000.
Common Causes
Typical Repair Cost
Based on 33 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P0732, 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 (29)
Transfer Case Actuator Motor Failure
Transfer Case Actuator Motor Failure
Aisin 8-Speed Transmission Jerking
DCT Dual-Clutch Transmission Shudder & Clutch Wear - F82/F83 M4
Transfer Case Failure - xDrive Models E84/F48 X1
xDrive Transfer Case Stress & Fluid Degradation - F98 X4 M / F98 X4 M
xDrive Transfer Case Stress & Fluid Degradation - F97 X3 M / F98 X4 M
Transfer Case Actuator Motor Failure (xDrive AWD System)
xDrive Transfer Case Actuator Motor Failure - E70/F85/F95 X5 M
Transfer Case Actuator Motor Failure (All xDrive Models)
DCT Dual-Clutch Transmission Wear & Judder - F10 M5
SMG Hydraulic Pump and Clutch Actuator Failure
SMG III Hydraulic Pump Failure - E60 M5
10R80 (10-speed) Harsh/Delayed Shifts and Shudder (Software/Valve Body Related)
10R80 10-speed transmission harsh/erratic shifting and torque-converter shudder
6R80 6-Speed Automatic Harsh 1-2 Upshift / Erratic Shifting and Lead-Frame Solenoid Body Failure
7G-Tronic Transmission Valve Body Failure
9G-Tronic Harsh Shift
Harsh Shifting and Delayed Engagement in 7G-Tronic Transmission
722.6 5G-Tronic conductor plate failure (limp mode, stuck in 2nd gear)
FAQ
What does P0732 mean?
P0732 stands for "Gear 3 Incorrect Ratio." This code means the transmission control module detected that the gear ratio in 3rd gear does not match what it expects when the transmission is commanded into that gear. The computer compares input (turbine) speed to output shaft speed; if the math for 3rd gear is wrong, it sets this code. It usually points to internal slipping or a hydraulic/electronic control fault rather than a sensor reading error.
What are the most common causes of P0732?
The most common causes of P0732 are: Low or dirty/degraded transmission fluid, Worn clutch packs or friction material in 3rd gear circuit, Faulty shift solenoid for 3rd gear, Valve body or pressure control problems, Internal mechanical wear or damage in the transmission, Clogged transmission filter restricting flow, Faulty input/output speed sensor giving skewed data. The specific cause varies by vehicle.
How much does it cost to fix P0732?
Repair costs for P0732 range from $100 to $12,000, depending on the vehicle and root cause.
Which vehicles are affected by P0732?
Au7o has documented P0732 across 29 vehicle models from 13 manufacturers: Acura, BMW, Chevrolet, Ford, GMC, Honda, Jeep, Kia, Lincoln, Mercedes-Benz, Nissan, Porsche, Volkswagen.
Sources (12)
- mediaMB Medic: 722.9 7G-Tronic Valve Body & Conductor Plate Must Read
- manufacturerECU Testing: Mercedes 7G-Tronic TCM conductor plate failure
- ForumBenzWorld: 722.9 7G Will Valve Body Fail cause Clutch Wear/Fail?
- otherCarComplaints: Mercedes 722.9 7G-Tronic Transmission Problems Cause Lawsuit
- manufacturerIscanTech: Mercedes-Benz 7G Transmission Removing Valve Body
- ForumBenzWorld: Problem with the 7G-tronic on my CLS350
- ForumSOLVED! - Sudden loss of 3rd/4th gear (4L60E) - GMTNation
- ForumTransmission slipping in 3rd gear - SilveradoSierra.com
- articleMost Common 4L60E Transmission Problems & How to Fix Them - Motorverso
- ForumFord F-150 10-Speed Transmission Lawsuit Over Harsh Shifting - CarComplaints.com
- TSBTECHNICAL SERVICE BULLETIN - 10R80 Harsh/Delayed Shifts (NHTSA TSB PDF)
- articleClass Action Filed Over Ford 10R80 Automatic Transmission Problems - ClassAction.org
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.