Throttle Range Calibration After Battery Disconnection
#21
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.
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.
The following users liked this post:
Downey (09-24-2022)
#22
#23
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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
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
Last edited by Don B; 01-19-2019 at 10:48 AM.
#26
+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.
Hopefully this cures some of my non linear throttle performance.
Last edited by Staatsof; 04-19-2019 at 08:51 AM.
#27
#28
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Location: Crossroads of America
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Cheers,
Don
The following 2 users liked this post by Don B:
Arelem (04-19-2019),
Jim Kristeff (03-18-2023)
#29
#31
#32
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.
#33
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!
Last edited by scrannel; 03-24-2023 at 08:12 AM.
#34
Resetting Throttle body after battery disconnection or replace
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
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
#35
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
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
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