Can anyone provide the answer to this mystery? I have received the "Failsafe Engine Mode" alert. Oddly enough, my cruise control switch does not illuminate when this alert comes on. Can any Jaguar Technician throw me some help on this please? I've read previous threads regarding this, however I'm not clear there is one answer to this one.

Thank you,
Mick's Jag

 

Did you read the OBD codes? If so what are the codes and what were you doing when the FailSafe came up?

 

The cruise control is shut down when it goes into failsafe mode. Normal.

 

Gus,

I was simply driving. The alert came up after about 12-15 minutes of driving. The driving and operation of the car did not change at all. I shut the car off and the alert went off. I drove for about 10 minutes and it showed up again. It seems to clear the code when I shut the car off. I do not know how to check the codes. I do not own any electronic devises to do so with. Any thoughts?

 

The 'restrictive performance' status limits the car to 3000 rpm which will allow you to drive normally if you don't drive aggressively.

Take it to any of the auto parts stores that read OBD codes for free. Surly, you must have set one or more by now. We need that information to provide any more feedback. It would also be nice to know the year and model of the car.

You have got to resolve the RP and the cruise control should take care of itself.

 

If you are in the states take it to any garage or AutoZone and get a read on the OBD Codes, if you are out of the country take it to a garage and let us know the codes. This is the first step in trouble shooting your car. Without it you are shooting in the dark. GET THE READ ON THE OBD!

 

Hi Tom,
When do you think people will understand that reading the OBD is important and should be the first thing you do?

 

Check the plug connection at the TPS (right side of your throttle body). I had the same message as you and the fix was to change out that plug with one that has gold connectors. Gus has information on his web site about this fix.

Your engine should have entered limp mode reducing your RPMS to 1000 - 1200. When it happened to me on my 2000 XK8 (3 times in one day) the "Limp Mode" just about got me to the curb. I was doing 40 mph at the time and more or less coasted to the curb. I had zero power and you can put your foot to the floor and sill have zero power. Shutting down and restarting resets the computer but that didn't last very long for me, as it was the same for you.

 

If this is your problem you should have a P0121 OBD code.

 

I'm in the USA (Massachusetts). It's a 1998 XK8 Convertible with 66,000 miles. I must be the luckiest Jag owner in the planet, as I have never had to bring it into the shop for repair do to a problem (other than a recall). I simply have kept up the maintenance of the vehicle, and put a battery in (2) years ago.

I just brought it to the local Jaguar dealer. They ran the codes, and came back with it needing a brake switch. I'm not sure why, as the brake lights work fine when the alert signal is on.

I do not lose any power at all when this happens. The RPM's go well above 3000, and the car's performance does not change at all. I'm stumped....

 

I called the dealer and got the code P1571. They re-confirmed it's the brake switch. Is it possible that one of the functions of the switch is failing, but still enabling the brake lights to work?

 

Yes, I've heard of several folks replacing these and curing the car.

 

Could be the cruise control cancel is not working in the switch. Maybe why Cruise is not working.

 

You receive a Failsafe Engine Mode and it's caused by a break switch?

 

I'm having the switch replaced tomorrow morning. I will keep you posted.

 

All set.... It was the brake switch.... Thanks to all.