OBD Is a well defined standard. The chips in the readers are pretty standard, and I would not be surprised to see the same chip in a $200 reader as a $11 reader. Yes... the quality of the circuitry may vary... and I actually agree with you that leaving an ODB reader plugged in 24/7 may cause an issue in some cars (including battery drain). However, I would not disuade anyone from buying a well reviewed elm based reader to diagnose a problem with their car. Dealers are in the business to make (aka take your) money, and a well informed customer and his money are less likely to be taken for a ride.

 

When I started this post my intent was to see if everyone on the form had a code reader to see what type of problem they had if the MIL lit up. More of an educational tool to make sure that the dealer or indie weren't pulling your leg with an expensive fix. Although it has taken off in different directions it still comes back to when the MIL lights up you have a device to read the code and look up the fault. Using it in that fashion shouldn't be a problem with the electronics as when checking in this fashion you don't need the engine running to see the problem. That's all.

 

Exactly. Happened to me with my 2013 XJ a few months ago. I left my ELM327 OBDII reader plugged in when I shut off the engine. The next day, when I started it up my dashboard went bonkers with one error message after another. My Jaguar service adviser told me to always unplug that OBDII reader and not worry about all those error messages. No codes were reported and no more error messages.

 

I have 3. I'm rich. LOL!

 

Those rare things you're trying to use to justify the over-the-top warnings are less injurious than the commoner things caused by chafed wires or low battery volts.

They DO NOT cause damage.

 

Nobody mentioned mongoose cable,through it is not a simple code reader. It's a J2534 diagnostic cable. The Mongoose JLR is one of the new approved interfaces introduced by Jaguar who are dropping support for VCM. It is a cheap good quality cable covers all obd reader functions.

 

Well EJ . . . actually they have! Read posts #2 and #14 here . . . and, by no means an accurate count, but at least hundreds of occasions over many dozens of threads identical to this . . . but it seems repetition is good for the soul!

Some learn; some ignore; and some deny . . . but the nature of Jaguar Forums is that each may weigh up the advice offered, then please yourself. What all of us should try to guard against (and in this, I support JagV8), is the advancement of "urban myths" - in this case, the wholesale denigration of low cost, proven OBDII diagnostic aids.

No-one here should deny the right of others to form and hold whatever belief . . . even in the sacred realm of maintaining your Jaguar! But, please take great care when you begin to advance those beliefs here as technical advice to others. Quoting Google based and "other internet sources" as "evidence" per se without case specific examination is like relying on Wikipaedia in the face of its own oft repeated warnings of "citations required" . . .

Cheers

Ken

 

Ken,

As you said, "in the sacred realm of maintaining your Jaguar" - your good advice is like a sermon from the pulpit of the Church of the Devout Skeptic. I go there, too. Amen.

Stuart