I took the cat out for the first time this year, and within 30 minutes I got the restricted performance flashing. OB2 tester shows a bad coil. I had a spare coil pack which I know to be good so I set out to change it out, of course it was cylinder #8 the hardest to get to.
I also knew my battery was pretty old (8 years) and the problems that can cause so I bit the bullet and purchased a new battery. After installing the battery I got ASC/Traction control flashing along with engine failsafe, the code reader showed a Throttle Position Sensor fault. Nothing happens when you press the pedal. I put the new battery on a charger just incase it was a little low but no change. Can anyone throw some light on this.

Regards,

 

First, are you certain the new battery was not connected backwards? If not. do a hard reset by removing the negative cable from the battery and touching it to the positive post for a few seconds.

Then reconnect, check that the connections are tight, and turn the ignition key to position two for 30 sec. before starting the car.

 

Thanks RJ237,
That seems to have fixed it!

 

Through research, I found that the accelerator pedal also needs to be retrained after a hard reset. Here's the full procedure I do for a hard reset now (kept as a note in my smart phone and also a printout in my glove box:

Jaguar Hard Reset:
Detach Negative connector and short to Positive for 30 seconds. Replace and tighten negative post to battery.
Turn ignition on, don't start.
Reset windows ("roll" up and down individually, holding switch at each position until you hear a light "click" from inside the door).

With switch in position II, (not started), slowly press accel pedal through kickdown detent to the floor & hold 5 seconds. Release pedal and repeat 1 more time.

Start engine, idle until operating temp is reached. Switch off.

Restart, idle for 2 minutes.

Apply foot brake, shift to drive, idle for 2 min.

Then, drive for 5 miles of varied conditions.

Reset audio and climate controls if needed. (Note: all of your OBD smog-readiness monitors will be reset, a rude shock if you're due for a smog test. There is a specific procedure to reset them, but 300 miles of varied driving may well do the job. Road trip!)