Why am I receiving a communication failure with all modules?

Check if the OBDII cable is working. change to another cable to confirm


Check if the OBDII function is communicating properly


Check if there are any issues with the vehicle itself
Check if any other vehicle has the same issue;

If all vehicles are not communicating, please try another OBDII cable.
If this is the only vehicle not communicating properly, please check for problems with the vehicle itself.