www.jec.org.uk

My 1999 S Type is suffering a variety of electrical problems and the Jaguar agent says the Rear Electronic Module needs to be replaced. I have sourced a second hand one. I am told that configuration data needs to be uploaded from the old module and downloaded to the new module - something that I obviously can't do myself. Is this true or will it be ok just to unplug the old module and plug in the new one ?
Many thanks.

Are you sure that the battery is in 1st class condition?
An aging example leads to many strange problems.

Yes, it's a new battery. Also I have taken the car to the Jaguar agent and they have diagnosed a faulty rear module.

Problem solved ! A local garage here in Spain fearlessly removed the old module and plugged in the new, and all the electrical problems (essentiall consisting of spurious error messages) have gone away. Fingers crossed !

Well done, Jef.

It is very rare that reprogramming is ever required following the fitting of an identially numbered genuine module. Most are just plug and play.

You might tease off the case of your old unit and see if there is any copper based verdigree evident on the pc board. If there is, then you might investigate the spare wheel well for a build up of moisture or even standing water. Any standing water could indicate a leaking boot seal or around the rear light clusters. I used to drill a 6mm hole at the lowest point in my S-type wheel well. At least that gave an automatic drain point should ever the tide have come into the boot!

Mike K