Hi. I have a jaguar s type r 2007 with 67000 miles on it and recently I had rear differential replacement on it under extended warranty. After the differential replacement every time I drive at the speed of 100 mph the cruise not available warning appears on my dash board, I do not engage cruise while driving at 100 mph the warning just comes and there is no CEL and any codes and the warning stays there until I turn off the ignition and restart the car. The car also slightly jerks when it hits the 100 mph mark on the speedometer and then continues to drive fine. This problem did not happen before the differential replacement as I drove it over 100 mph many times on highway before. I dropped the car back to the Jaguar dealer and they could not pin point what the problem was, they just updated the ECM and TCM but that did not solve the problem. Kindly help.

Welcome to the Club, Muhammad.

 

I am afraid that I have not experienced that Dashboard message, but on the other hand I have not experienced travelling at 100mph either, with national speed limit of 70 mph in the UK.

 

I guess your S Type has a 4.2 litre supercharged engine which could all be going into top gear when driven at 100mph and it could be a slight jerk from the gearbox.

 

I am slightly tempted to take my S type out onto the local dual carriageway and give it a bit of a power and see if it happens to me,  but the speed cameras and the local police take a dim view of exceeding the speed limits.

 

Regards,

 

Peter.

Cruise is not designed to operate at speeds in excess of 80MPH. That is why you are geting the message.

Dave

Very useful to know, Dave.

 

When I use CC I usually set it at 1950 rpm which gives me 68 mph and the best fuel economy.

 

Peter.

I use it at around the same as you. I had the cruise problem when I drove to Germany and reported it to my dealer when I came home. Apparently they have had several such enquiries.

Dave

Hi Dave,

 

I live at the edge big conurbation, and the roads are frequently not suitable for cruise control, and when on the motorways there are spots where you know that you have to drive the car.

 

I have 130 miles to drive tomorrow on the M6 and the M1 and I can't see myself thinking of switching on CC.

 

Peter.

Hi Pete

How do you set the revs at 1950 rpm ?

Keith.

Hi Keith,

 

With your speed at about 68mph on a flat road, your rpm should be 1950 with the 2.7 litre diesel engine. I then switch on CC.

 

A bit different with the petrol engine.  I use 1950 revs as the second turbo charger comes in at 2000rpm.

 

I assume you have the 3 litre petrol engine which is very different.

 

Regards,

 

Peter

Hi Muhammad,

 

I have an 04 V8 (non S/C) I've had it over 100 on several occasions and never had any warnings,

 

if this didn't happen until after your diff replacement I would stay on the dealerships case until they get it sorted, after all it was fine until they messed with it.

 

Good luck

 

Mike