WJdiag Free is made for Jeep Grand Cherokee 2002-2004 year, WJ/WG models with 2.7 CRD engine. It can read and clear Engine and Transmission fault codes.
WJdiag is working with Bluetooth ELM327 device through OBD2.

We highly recommend to use good ELM327 and avoid fake Chinese devices.
Most of 10 EUR Chinese ELM327 devices do not support ISO 9141-2 and J1850 data protocols that are needed for Jeep WJ diagnostic and will display connection error even if some other generic diagnostic app can connect to some module (without getting any useful). WJdiag is customized app for Jeep WJ/WG, it can not connect with your car if your ELM327 can not handle data that Jeep needs. There are no problems with good ELM327 devices and they can connect to car correctly.

With WJdiag Free you can see all fault codes, with explanation, stored in Engine and Transmission of Jeep Grand Cherokee 2.7 CRD. It does not work with 3.1 diesel and gasoline models of Jeep.

Engine support for 2.7 CRD models:
Engine fault codes reading with ID code and code explanation.

Transmission support for 2.7 CRD models:
Fault codes reading with ID code and code explanation.

Data logging, Live Data, Inout/Output values and Tests/Coding is disabled in Free version. If you would like to access to all control units of your Jeep Grand Cherokee, then you should buy WJdiag Pro version. Just test your ELM327 compatibility with Free version.

All other control units are limited on WJdiag Free version. You can connect to other control units, but you will see control unit information only – like part number, software version etc. With recognizing control units you can see if your ELM327 is compatible with Grand Cherokee or not.