I was driving on the HWY 12/10/10 as I tried to turn on cruise control my car lost power wouldn't go over 10 miles the message gearbox fault, and engine system fault appeared. I pulled over off the hwy turn the off, my car started system message reset. However this morning my car would not start temp outside 17, sounds like a belt maybe loose. Dealer stated issue is with gearbox and engine system fault cost $1912.79 to repaired. Dealer stated the issue with gearbox may have (air) in engine which cause the car not start. Yes this what I was told today. Has anyone experiences this issue before?

Jag 2002 X 3.0
105256 mileage
owned since 2007

$1912.79 repaired the cruise control, gear box, and labor.

 

I had a very similar problem (see my poswt on Gearbox Fault and DSC System Fault). The dealer told me it was my throttle body; cost ~$2000. Funny how we got the same symptoms, same messages, same cost to fix but different cause.

Mark

 

I think I would ask them to explain what their fix entails( what they plan to do for that price). Does it sound like they're being 100% truthful.
I had a dealer tell me I needed to replace the transmission (($3750) because battery acid had dripped on the transmission wiring harness connector that runs underneath the battery compartment (great engineering). They said no they couldn't splice in a new connector. Well I'm hard headed and couldn't see the sense in replacing a perfectly good trans. I cleaned the connector with baking soda/water dried it, sprayed it with clearcoat then silicone and wrapped with electical tape. Cost probably less than $2 savings priceless. I haven't experienced any problems with that connector in 3 years, and the trans is working perfect too.

 

I wish Brutal or Thermo would comment, but yours sounds like the throttle body. Maybe even a vacuum leak.