I had to jump start my 2008 XK this morning. Since having done that, everything seems to be fine but my cruise control. The dash says something like "Cruise Unavailable" or something to that effect. The clock even stayed on time. Is there something I need to reset? Thank you in advance for any assistance.

 

I had a similar issue on my XKR when I first purchased it....battery was down on voltage.
Replaced this and no probs since......by the way it looks your in for a battery too !!!

 

There are a number of OBD II codes that, before anything else, shut down the cruise control. Do you have a CEL? Stop by a local auto parts store and have them test your charging system and battery condition but first ask that they read any codes stored. Get the actual codes and come back and we can help with more specific information.

 

Needing to jump a car means something is fundamentaly wrong, the battery is shot, or the alternator is shot, or there is a parasitic drain in the system. It needs to be fixed for sure. Jumping a car is a risky activity....if the battery is below about 10 volts, you stand a good chance of frying the alternator as it cannot recharge a battery this low without overheating. Whenver my car won't start, I put a meter on the battery and make sure of the voltage. I then put it on a 10 amp charger until there is enough power to start the car, then put the meter back on the battery and make sure it reads close to 14.4 volts, meaning the alternator is working. then you will know what to do. Most people don't have a load tester but they are cheap at Harbor Freight. Put this on the battery and run the load test, then you will know what the battery is doing.

 

I should have mentioned that I just went through this issue with the XJ8. I had the auto lights acting up like something was wrong with them, flashing on and off. The next morning the car was only clicking when trying to start. I charged the battery but it would only go to 12.12 volts..it was shot, should have been 12.56. Replaced the battery and all is well. This battery was a good quality 60 month battery and was only three years old.

 

I should have moved this thread to the correct XK/XKR 2006 onwards forum yesterday.

Nevertheless, good advice above on battery condition and getting the codes read which is equally relevant to both models.

You have a 2008 XK which has an even more tortuous jump start procedure than the earlier XK8/XKR.

Whilst it's possible some damage could have occurred to the XK if you were running the jumper car engine, it's unlikely as you would probably have considerably more issues than a cruise message.

The message will be CRUISE NOT AVAILABLE (?) indicating Cruise control or Adaptive Cruise Control malfunction. On the XK/XKR, this will continue to display until the until the fault / code is cleared.

Graham

 

I'm curious about the official, Jaguar-blessed method of jump starting an XK8. Can somebody tell me where to find that please? (I have JTIS if it matters)

TIA

 

Here's the relevant extract from my handbook (MY2005)

Emergency starting
! WARNING:
Do not attempt to jump start a vehicle which may have a frozen battery.
Rolling start
A start by pushing or towing cannot be achieved on a vehicle with automatic transmission.
Emergency starting using jump leads
Both the booster and discharged battery should be treated with great care when using jump leads. Always use high quality leads capable of carrying the starter current of the vehicle to be started. Before commencing, the following precautions must be taken:
1. When using a separate battery ensure that the charged battery is placed near to, not on, the vehicle with the discharged battery.
2. When using a jump start vehicle, ensure that both vehicles electrical services are OFF, the handbrakes are ON and the transmissions are either in Park or neutral.
Where the jump leads are of a different colour, e.g. red and black, use red for positive (+). Take extra care to avoid crossing the polarity when using cables of the same colour.
Caution:
1. If using a jump start vehicle, under no circumstances should the vehicles touch. This could establish an earth connection, which may cause sparks and damage.
2. Do not run the jump start vehicle’s engine when boost starting a Jaguar vehicle. If the jump start vehicle’s engine is running and the jump leads are disconnected, damage to the Jaguar vehicle’s electrical system will result.
3. The booster battery voltage must not exceed 12 volts.
The following procedure must be followed exactly, being careful not to cause sparks:
1. Apply the handbrake, select Park and turn off all the vehicle’s electrical services.
2. Remove the luggage compartment floor panels.
3. Unclip the positive (+) terminal cover.
4. Attach one end of the red jump lead to the positive (+) terminal of the booster battery and the other end to the positive terminal of the discharged battery. Make sure that a good connection is made. Do not allow the vehicles to touch.
Caution: Do not connect the negative jump lead directly to the negative (–) terminal of the discharged vehicle.
5. Attach one end of the black jump lead to the negative (–) terminal of the booster battery and the other end to an earth point on the vehicle being started. (Use the spare wheel retaining bolt.) The earth point must be at least 305 mm (12 inches) from the discharged battery. Make sure that a good connection is made.
6. When started allow the engine to idle for five minutes before disconnecting the cables.
7. Disconnect the black jump lead from the earth point and the booster battery negative (–) terminal. Disconnect the red jump lead from the positive (+) terminals of both batteries.
Note: Disconnection is done in the reverse order to the connecting procedure.
8. Refit the positive terminal cover.
9. Refit the luggage compartment floor panels.

I assume the guidance to not using a booster battery of more than 12 volts means not 24, rather than 12 point something or even 14!

 

Thanks. I think your assumption re: battery types is correct. All of these lead/acid thingies are called "12" or "24" or whatever, but in truth it's a multiple of one cell's voltage ... 2.xx volts per cell, I forget exactly.

The procedure cited seems like a good one for just about any modern car I can think of. Only other thing I would like to see is both cars turned off before removing cables. (Of course we can't have it this way If the jumpee can't then be restarted absent the connection to the jumper.)

 

2.105v/cell. (not trying to be a know-it-all, just got done an extensive electrical system re-do on the boat, where battery voltage and amp/hrs are everything).