Need help my 2006 xjr about 92,000 miles on it
check engine light came on, I plug in the code reader it gave me P0300, P0316, P0302, 04,06,08. weird thing wiring on it is fine, car runs smooth spark plugs & ignition coils are fine.

P0783, transmission fault & restricted performance lights come on whenever I set car on cruise control or sport mode. Gears do feel like they slip. they come off when I turn off & on the car.

 

First guess batterie ,check with engine off 12,5 volt it should be ,engine on 14,6volt so the alternator works properly.
check your grounds in the front right and left behind the headlights . Carefull those break off easely ,clean them with a brush or sandpaper reconnect
I do have some time and check if I can find more info related to the codes the codes.
there are downloads available in the x350/358 forum , scroll a bit in the stickies

 

First guess batterie ,check with engine off 12,5 volt it should be ,engine on 14,6volt so the alternator works properly.
check your grounds in the front right and left behind the headlights . Carefull those break off easely ,clean them with a brush or sandpaper reconnect
I do have some time and check if I can find more info related to the codes the codes.
there are downloads available in the x350/358 forum , scroll a bit in the stickies

 

 

 

 

Did you change your ignition coils lately?

 

misses will cause sloppy shifting but add trans fluid asap

 

Before filling I would check the trans fluid level first.

If it is not low you could have internal damage resulting in fine metal shavings that cause a blockage in the valve control body which can cause slippage as the valves are not
operating properly. The valves have fine mesh screens but if the shavings are small enough.............

This obviously is the worse case scenario so hope it is not the issue.

If you drain and drop the pan you may see metal fragments on the magnet. Which would obviously be bad news.

 

I’ll check on those, I’ll keep ya’ll updated.

 

I did check engine light went away and came back on the two days late.

 

What are the codes now?

 

It still reads the same but the transmission was rebuilt and shifts fine, there’s no crack head gasket, spark plugs and coils are fine. Could it be a sensor or a electrical problem?