Left house the other day in my 2002 X type 2.5 and it shifted down and wouldn't accelerate properly. Made my way back home after turning around in a driveway but reverse wouldn't work. It was like giving it gas when in neutral. I looked for any warnings in dash but none. Check engine light has been in for years. Codes always indicated O2 sensors but mechanic told me it was a glitch with the X type so I've never bothered with it. Tonight I had codes ran and still just O2 sensors but the guy said his reader may not pick up transmission codes. My questions: Is it in limp mode? Does limp mode affect reverse? If my O2 sensors really are bad would that throw me into limp mode and affect reverse? I have had no indications that my transmission was failing and the car has been running great. Recently had all coils replaced during tune up. I love my car and want to keep her a few years longer. Only 77k miles so surely she's not done yet! Any help or ideas?

 

You have the reverse piston failure common to many of the early cars (and also experienced by every other make that used this JATCO506E transmission: VW, Mazda, Land Rover and others - it is not a "Jaguar problem".

Unfortunately this usually means a transmission rebuild (the failing parts were upgraded by the 2004 model year) but then your car will be good for another 70,000+ miles.

 

The check engine light codes for O2 sensors and your reversing issues are not related. Definitely sounds like it is in limp mode. Was the car working perfectly and then all of a sudden out of the blue you cannot get it to go into reverse? Did that happen once or now you can't get it into reverse at all? Might be as simple as something in the gear shift mechanism or could be more serious. Impossible to say.

If you could post the code number you are getting that would at least be a place to start.

Have you ever had the transmission and transfer case fluids changed? The car is 15 years old even if it does have low mileage for its age. That might be a place to start, but from your brief description you might need to take it to a competent transmission shop.

You mention the check engine light has been on for years. There is no "glitch" that causes the light to go on for no reason. It was on because you have an issue. I would have to question that diagnosis by your mechanic.

 

Limp mode does not inhibit reverse in the transmission! Please read my posting above regarding the loss of reverse. The most likely cause is a cracked reverse piston (a known issue in the early JATCO506E).
And I agree that the mechanic in question needs to be questioned again. If the code indicates that there is a fault with one of the O2 sensors then there is a problem -and continued driving without correcting the problem will eventually damage the catalytic converter ($$$$$$).

Comment from the original poster?