They display the error code that points to the problem a vehicle is having.
There are many OBDII scan tools that give basic engine codes with most unable to read ABS, SRS, or transmission errors.
Transmission codes are in the P0700 to P0799 and above P1000 with most basic scan tools unable to read these.
With that said there are some that can read transmission codes but have a higher cost.
There are many units available with those below our picks for best scan tools that can read transmission codes.
As always be sure to read reviews on Amazon, Forums, or elsewhere to be sure a unit is a good fit for you.
*This post contains affiliate links.
Our Picks for Best OBDII Scan Tools That Read Transmission Codes
- Launch Creader VII
- ANCEL FX2000
- Autel MaxiLink ML629
Launch Creader VII+ OBD2 Scanner ABS SRS Transmission and Engine Code Reader Diagnostic Scan Tool
Launch makes many good OBDII scan tools including the Creader VII.
Here is a video showing the transmission data starting roughly at minute 10:25.
ANCEL FX2000 Vehicle OBD2 Scanner Automotive Car Code Reader Check Engine ABS SRS Transmission Diagnostic Scan Tool
The ANCEL FX2000 is a new unit for 2019 built with many nice features including reading transmission errors.
Autel MaxiLink ML629 OBD2 Scanner Upgraded Version of ML619, DTC Lookup, Ready Test, ABS/SRS/Engine/Transmission Diagnoses
The Autel MaxiLink ML629 is another nice unit to find transmission problems.
Finding a good OBD2 scanner that can read transmission codes is like finding any other tool.
It must be easily understood by the user and what works for one person may not work for another.
Make sure any unit bought is compatible with the car or truck you plan to work on.
Most units are likely to be compatible but it is always best to make sure before buying a unit.
Also a unit that can be updated is good to have for adding data the tool can read and expanding its ability.