Why are Jaguar Dealerships not aware of the battery issues. A memo should have been sent to all of them

 

Please excuse my lack of understanding, but isn't the problem with OBD code readers simply that people pull them from the port without first following the reader's instructions regarding termination of the session? I thought if you formally end the code reading session and put the reader in a neutral state before disconnection, the car also returns to its pre-connection state, so there's no residual battery drain. Wrong?

 

Sounds right to me.
I always back right out of the code reader before unplugging it (iCarsoft LR V2.0) and despite using it dozens of times I have never once had a battery drain problem.

 

This is correct. The problem is many owners live in areas that require an annual/bi-annual emissions inspection that requires hooking up the test equipment to the OBD port and many have experienced the battery drain after the inspection due to the improper disconnecting of the equipment. Most cars and most OBD-II readers don't care if you don't properly shut them down before disconnecting so service techs may get careless if they're used to just quickly removing it when they're done with the connection.

 

That problem could be mitigated with better software design. You may have heard the question "Have you turned it off and back on again?" That does not restore normal operation here. It needs to be unplugged. The "won't go to sleep" issue is an unrecoverable condition, yet one easily foreseen. The design and implementation should account for that.

 

There's definitely an issue with the ECU software. In the UK, garages were told by the government not to plug any OBD to Jaguar cars as it had been informed by Jaguar's engineering team that the use of non-Jag approved OBD readers could lead to the communication port to be left permanently on. That's BS because I use one and by following the process of closing the session, the communication is stopped.

On Audis, unplugging the reader is all it takes to close the port.