My 1999 XKR is coming up Failsafe Engine mode and then restricted performance. The car is running fine, there certainly isn't any restricted performance. I have looked for codes on my ODBII reader but there aren't any shown. Any ideas please?
Many thanks Gerard.

 

no codes huh, I’ve always had a code when the F/S engine mode came calling.

first to do : do a hard restart, search on the forum if you don’t know the procedure.

second, check the battery voltage after the car has sitting overnight without any battery tender. It should read 12.6v or higher.

Any less and you should consider a new battery, in the meantime you might be able to rejuvenate the battery by keeping it on a battery tender whenever the car is parked.

Z

 

If you disconnect the battery be aware you clear all the OBD monitors. They need to be set (not clear) for smog test in many places, but the biggie for diagnosing a problem is that for each unset monitor a bunch of codes can't be flagged (because the car doesn't know what it can trust).

I would NOT disconnect the battery yet.

Instead I would look to see if all OBD monitors are set and for any that are clear try to find why.

I'd also use OBD live data to check sensors such as ECT & IAT and then check fuel trims to seeif they're OK or not.

Definitely do check your battery is good, though!