Just in case anyone does not.

see below.

Just like most other EMS.

Resetting kick down travel limits.

After battery reconnection, the engine management system must ‘re-learn’ the limits of throttle pedal travel.

This is to ensure correct adaptive settings are stored for kick down operation.

Re-programming is done with the ignition switch in positionII as follows:

Slowly press the accelerator pedal fully through the kickdown detent to the floor.

Release the pedal and repeat the action. Then stop.

Drive around a bit and you will see an improvement. If not re read the codes, and re-start and try again.

 

When replacing the battery, assuming it still has some residual charge, wouldn't it be worthwhile to connect a temporary 12 volt supply (or battery) across the leads so there's no loss of power during the change over?

 

Hi fluty,


Welcome to the Jaguar Forums! It's great to have you with us.

Yes, you make a good point that attaching a temporary 12 volt supply to the battery cables can obviate the need for resetting or recalibrating various systems whose keep-alive-memories are cleared when the battery is disconnected, and some Jaguar service documentation makes this recommendation. Unfortunately it won't help if the old battery becomes depleted prior to replacement. Also, there are certain operations such as alternator or starter replacement when connecting a charger or power supply would be inappropriate, since you don't want any voltage at all on the battery power cables.

When you get a chance, please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don

 

Thanks Joe..
Noticed you are from Stoke on Trent...
I am in Los Angeles Ca USA..
had several friends.. all bikers.. from stoke on trent.

sincerely, Brad Lewis

 

 

+1 Being snarky about supplying superior knowledge undercuts it's value. More than one of us had never seen this before and had no issues with the car WO doing this. But it's great to have the info now!

Hopefully this cures some of my non linear throttle performance.

 

Doesn't pressing the accelerator pedal, with the engine not running, flood the engine? It did on other cars I have owned, like my Sterling 825SL and my Eagle Vision TSi.

 

On your '04 S-Type, unless the fuel injectors are energized (which only happens when the engine is rotating), no fuel should be injected into your combustion chambers no matter how many times you depress and release the accelerator pedal (which is connected to the throttle body electronically - there are no traditional cables).

Cheers,

Don

 

I discovered this accidentally. The weird thing is it's not guaranteed to happen. It wasn't until the third time that swapped out my battery that something was wrong with the throttle.

 

It seems like a harmless ritual to me, can't hurt. I'll try it tomorrow, without disconnecting battery though.

 

It doesn't always make a change, but last time on my XFS 3.0 D after a long battery disconnect, the throttle acted very crudely. Performing this reverted the response to how it was before. Something definitely happened.

 

This would only happen on a car with a carb or carbs. Fuel injected cars will not do this. On carburetors there is a throttle pump that gives an extra squirt of fuel every time you pump the throttle. This is to give you enough power when you suddenly need it whilst the engine is running. However, because it is a mechanical pump it does not turn off when the engine is not running. Therefore, so long as there is sufficient fuel in the float chamber, you can flood the engine by repeatedly pumping the pedal even with the ignition turned off.

 

I'm a bit late to the party but have a 2008 4.2 (recently purchased) that seems to have a "hair-trigger" throttle response once warmed up. Would disconnecting the battery and retraining cure this? Thanks Sorry I seem to have posted twice -- ignore this post!

 

I have a fully restored Jaguar S-type (base) V-6 with its 6 speed automatic BMW transmission.
It was made in England by Ford and shipped to the US.

When the battery is disconnected or replaced, certain things have to be reset by a hand-held computer plugged into the car's harness for this.
In addition, the throttle body has to be reset in this car. This may work for all S-type models but my engine is a V-6 - not a V-8, so I don't know if this will work on a V-8 engine.
It wouldn't hurt anything to try it, Yes? Yes!
This is accomplished by turning on the key and then slowly press down the gas pedal to the floor and let it up. Do this twice. Then start the car.
In my experience with Jaguar dealers today, most of their mechanics do not even know how to do this. This can cost you a lot of money charged by them for nothing.
I took my car to a well-known dealer to get its rough running fixed by them after replacing a battery. They charged me a lot of money and when I left the facility the car barely ran.
I almost didn't make it home. I checked into this forum back then and someone replied back to me about resetting the throttle body.
I did this and the engine immediately ran perfectly from then on.

Even the best mechanics - not at Jaguar dealers - don't know how to do this and it must be done.
The S-type jaguars were made or a period of years and then discontinued, as you likely know.
I do not know if your Jaguar in the year 2008 4.2 (is this a v-8 or v-6?) will work right if you try what I suggest but it couldn't hurt anything.

Hope this helps.

Scott

 

Thanks Scott. My car is a 4.2. Will give it a try and report back! Thanks