Drove around town this morning, and shut down at the bank. Hopped back in a few minutes later, engaged the starter and the engine spun over fine but no start. Checked everything I could think of, it had some codes and "transmission failed" warning. I then noticed that the Sport mode button seemed like it was half up, half cocked. I recycled it a few times and engine started normally. I then did about a dozen start cycles and it performed normally. Would you guys agree that I may have bumped the button inadvertently, thus creating the start failure? Thanks... Bob

 

Do you have the codes? If so please post them. Not sure that the sport mode switch would have prevented the car from starting but the shifter not being in “P” or “N” properly could have caused this momentary glitch. If you experience this issue again you may want to move the shifter and see if it is the issue and if it is then I would consider readjusting the shifter cable first.

 

Hey Gus, Just one code stored, it was P1111, fuel/air mix. If we assume for a moment that the sport button was not fulling engaged somewhere between ON or OFF, would it be possible to get this code? Dunno. What's your read? Thanks, Bob

 

Your car is a 2000 XK8 and the P1111 means all on-board diagnostic tests have been completed see link below.

Link http://www.jagrepair.com/images/Auto...7_ECM_2000.pdf

You can use this to help the next time the car does not start.

Link JagRepair.com - Jaguar Repair Information Resource

I hope this helps

 

I went several days and multiple starts before it did it again. I made about a dozen or so start attempts before it started. the starter was cranking like crazy, lots of volts. Foot on brake, no throttle / gas pedal. Codes came up as;P1000-on board diagnostics monitor/drive cycle test not complete. Next code;P1797 manufacturer controlled transmission. What the heck?Then it started up, I don't know what to think... I've made about a dozen normal starts since then, no problem.('till next time...)

 

P1797 is a code for the CAN communication from the engine controller to the transmission.

Are there any other codes or is that the only one?

If that is the only one and it only happens at start up and never while you're driving, I'd guess a dirty connection, the relay that powers the transmission control module or even a weak battery. These cars are finicky about voltage and old batteries can cause all kinds of strange behavior.

 

What does a CAN controller mean/do? ...and thanks for your input by the way...

 

Controller Area Network

It's one of the communication paths that these cars have in them for the different control modules to talk to each other.

For the CAN network, the instrument cluster acts as a sort of hub but if you don't have any other codes, then it is probably not the source of your problem since that would interfere with more than just the transmission communication.

 

This is the only code. I'm not gonna let it beat me...

 

Bob,
Please put your car details in your signature to help us.

As Gus says it can be shifter cable adjustment or (I believe) a connector on the transmission.
I don't think it will be the Sport button - it's either on or off - probably you just nudged something else.

 

I believe that yesterday when I parked the Jag, I set the alarm. When I got back and pressed the Disarm button, it failed to disarm. I used the key to unlock the door. I then attempted the start, the engine cranked over fine, but no start. I recall that I again tried all combinations of foot on brake, moving the shifter , clapped three times,ect, then pressing the ARM/Disarm buttons on the key pad...and it started. Later last night after consuming some beverages,I screwed around with the key fob again, and noticed that the Disarm button was intermittant. I have another key pad that works as advertised, and Arms/Disarms on every attempt. Do you guys think that the faulty key pad was part of the problem? Thanks, Bob

 

If I recall correctly you can set the alarm with the remote and turn it off with the key when you unlock the door with the key.

Note: As long as the transponder on the key is working.

 

Random seemingly unrelated electrical gremlins are often a sign of a failing battery. Do you know its age?

Might be worth a stop by the local auto parts store for a load test just to be sure.

 

+1 on what he said!

 

Battery is dated Aug 2011. Load tested good. I'm still suspicious of the first key pad. Did six starts today, no problems.

 

It's not impossible.
Some people have got similar errors from plugging in a duff OBD reader so maybe an odd code sequence coming from the fob would upset things. Keep us informed.

 

Car wouldn't start again today, but would start in neutral. What might I have to replace...?

 

I would verify it again before replacing the shifter selector switch it cost around $400.00+. The switch is mounted on the right side of the transmission and the plug is behind & below the Throttle body to the right.

 

There are three devices with mechanical adjustments that are involved in the start interlock system:

-- brake switch
-- shifter quadrant at cable
-- dual linear switch at shifter

They should all be checked for proper adjustment before replacement is considered.

When the car will crank but not start, check the following with the key at position 2:

-- does the interlock relay click when the brake pedal is touched?

-- is either P or N illuminated as relevant to the position of the shifter?

Failure of either of the above indicates the component out of adjustment.

Starting after jiggling the shifter or moving to N is a sure sign of problems with the interlock.

This condition can also be induced by a weak battery. A battery can pass a load test and still be weak because the charging system cannot keep up. Certainly load testing and returning to service without charging leaves the battery in a less than optimal state. Try a full 24 hour charge using a good charger and see if the problem goes away for a while.

 

I'm putting it on a slow charge now...