My 2000 S-type 3.0 (93,000 miles) does not show a fault but it indicates a P1580 code pend. My wife said it went into failsafe mode the other day but when I drove it for about 2 or 3 miles it was fine. However my OBD II shows the info listed above. What should I do at this point?

 

You should ask the question in the S-Type tech forum.

I've moved it for you.

Graham

 

I'd check battery voltage after car has stood for 8+ hrs (engine off). If at least 12.3V or so I'd see what happens. Below that and I'd replace it.

I'd look at / clean the contacts for the throttle body, too.