Transmission · Powertrain · generic (SAE-defined)
P0733: Gear 3 Incorrect Ratio
P0733 means the transmission computer measured an incorrect input-to-output speed ratio in third gear, indicating the transmission is slipping or misreporting speed in third.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0733 sets
With third gear commanded, the transmission control module (TCM) compares the measured shaft speed ratio with the third-gear design ratio. A sustained mismatch outside the permitted band causes the TCM to set P0733. The band and detection time are manufacturer-specific.
Common causes of P0733
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- Low or degraded transmission fluid
- Worn clutch pack used in third gear
- Faulty shift or pressure control solenoid
- Sticking or worn valve body components
- Leaking internal seals
- Incorrect input or output speed sensor signal
P0733 symptoms
- Check engine light on
- Slip or flare on the 2-3 shift
- Transmission skipping third gear
- Sluggish acceleration at moderate speeds
- Limp mode or stuck gear
How P0733 is diagnosed
- Read all transmission codes and record freeze frame data
- Check fluid level and condition
- Road test while monitoring input, output and engine speeds through the 2-3 shift
- Confirm speed sensor accuracy
- Check solenoid command and response
- Pressure-test or inspect internally if simpler causes are ruled out
Typical fixes for P0733
- Correct the fluid level or service the fluid
- Replace a faulty solenoid
- Repair or replace the valve body
- Replace a faulty speed sensor
- Rebuild or replace the transmission if third-gear clutches are worn
Replace parts only after testing confirms the cause — a code names the circuit or condition that failed a check, not necessarily the faulty part. We don’t publish per-repair prices; for what households actually spend on upkeep, see car repair costs.
Related codes & warning lights
P0733 FAQ
What does code P0733 mean?
P0733 means the transmission computer measured an incorrect input-to-output speed ratio in third gear, indicating the transmission is slipping or misreporting speed in third. The standard definition is "Gear 3 Incorrect Ratio."
Can I drive with a P0733 code?
Limit driving until it is inspected. Third gear is used often in city and moderate-speed driving, so slipping there builds heat quickly and can lead to further damage.
Why does my transmission skip from second to fourth?
If third gear cannot hold, the computer may avoid it or the shift may slip through quickly, making it feel as though third is missing.
Can P0733 appear with other ratio codes?
Yes. When several gears share a worn component or the fluid is low, multiple ratio codes can set together, which helps narrow down the common part.
Keep researching
More transmission codes
Sources
- SAE J2012 — Diagnostic Trouble Code Definitions (standard code titles)
- ISO 15031-6 — Road vehicles: communication between vehicle and external equipment for emissions-related diagnostics, Part 6: Diagnostic trouble code definitions
- U.S. EPA — Vehicle Emissions Inspection and Maintenance (I/M) programs
- U.S. EPA, 40 CFR 86.1806-17 — Federal onboard diagnostics requirements for light-duty vehicles
General information written by CarWhere Research, not a diagnosis of your vehicle. Manufacturers can add their own sub-definitions and test conditions; confirm with the factory service information for your year, make and model. Before paying for a repair, check NHTSA for open recalls and your warranty booklet: federal law requires an emissions warranty on major emission-control parts such as the catalytic converter and engine computer.