Throttle Range Calibration After Battery Disconnection
 

Hello everyone.

I have recently solved several issues with my 2003 Jaguar S-type after replacing the old batter with a new one. One problem had to do with reseting the throttle for proper gas-air mixture, especially during downshifting to a lower gear via the gas peddle. I took the car to Jaguar dealer and explained that after they charged me for doing a throttle body cleanout and for finding and fixing a short for the dash lights (speedometer and rpm + odometer gauge lights (found where I said it would be - behind the center console where the radio/CD player and air-conditioning controls are located), I then drove the car away from the dealer only to discover that I had an intermittent throttle problem when I stepped on the gas (bogged down - no downshift). I took the car back to the dealer and had the mechanic test drive it several times until he too found the problem occurring. But after he brought it back to the dealer shop, he could not find the problem or any fault indicators. He suggested that I replace the spark plugs, which also entails replacing the intake gasket. I knew this was not correct because the engine was tuned perfectly, idled and accelerated perfectly until the intermittent problem kicked in. They would have charged me $600 to replace six spark plugs and the intake gasket. All the care really needed (the dealer mechanic did not know this or did not apply it) was to reset throttle body by turning on the key (no engine start) and slowly stepping down on the gas peddle to its stop point and then push it to the floor. You do this twice and then start the car. This reset the throttle body and downshift peddle controls and the car ran great, including increased RPM and proper downshifting. This saved me thousand the dealer would have charge me for their ignorance trying to throw fixes at the car that had absolutely nothing to do with the simply correction required. After a new battery is put in the car, this procedure must be done or there will be problems that do not show up as a fault. Hope this helps.

The reason I posted the previous statements was to get to another matter and be helpful at the same time. After the used car lot I bought the jag from replaced the clock spring in the steering column, it malfunctioned (air-bag light came on) and all the control in the steering wheel went out - horn, curse control, and controls for the radio/cd player, including the volume for the radio/Cd player. I took the car back and the clock spring was replaced. I had the dealer check this installation for accuracy and it was find. All the controls work now, including the volume control on the steering column and on the dial on the radio head console - but no volume came back on. I called the corporate Jaguar - Range Rover and obtained the radio reset code for the vin number for my car - made in Britain for the US. There is a code but I do not know how to enter it correctly, as no code word ever shows up. Anyone know how to enter this code to reset the radio/CD player? It does not make sense that the volume of the radio/cd player would go out internally in the radio because a clock spring on the Steering column went out.

I appreciate your description on how to reset the throttle body but just need a little clarification. When you say to push down on the gas peddle to its stop point, wouldn't that be at the floor? How could you then push it to the floor.
Will it stop somewhere above the floor and then need to be forced all the way down?

Thanks for posting....but I'm dubious. I've renewed the batteries or had them in and out of both cars numerous times and never done this. Never had any throttle problems.

This procedure is part of the PDI, and should be done at first ignition on, (no start) every time the battery is disconnected. Span has to be set.

Please post the PDI for an S-Type. (I do not believe it exists, but can be convinced easily by it being posted.)

Isn't it weird how over the last 8 years on this and other jag sites no-one has ever needed to do this?

It used to apply to earlier cars...

Barney 100golf has posted about the resets that have to be done after the battery has been disconnected and that it will effect the way that the car responds.
http://www.jaguarforum.com/showthread.php?t=78977.

It's in JTIS. Article number JTP 935. S-Type: Pre-Delivery Inspection, Page 4 "Effects of Battery Disconnection"

"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 kickdown operation. Re-programming is done with the ignition switch in position II as follows:

Slowly press the accelerator pedal fully through the kickdown detent to the floor. Release the pedal and repeat the action."

Isn't it weird after over the last 8 years on this, you haven't even taken the time to actually look. I can't fix lazy, nor does it constitute error on my part.

Brilliant,

Is there a Smilie which says that.:icon_clapclap:

It's weird (*), yes, that no-one has raised this, we've not had cars unable to be driven and so on.

I still cannot find it in JTIS so I guess there's something missing in my version.

At least after all these years of no problems you've helped get to the bottom of this. Thanks indeed.

(*) it's not weird, as the PCM learns many values, including the accelerator pedal position sensors, all the time

JagV8, calling me derogatory epithets doesn't bolster your position. If you are unclear on how to use JTIS, try selecting the PDI button at the top. If you feel your information is incomplete, you can visit Jaguar's TOPIx website.

The good news is that hundreds of members have disconnected their battery and often replaced it yet not needed this. I expect that to continue to be the case but perhaps you'd like to add to the Stickies, and all future posts about battery disconnects, so people don't fail to do the PDI procedure.

BTW I'm one of the hundreds. I don't know how many times I've disconnected the battery as I've not counted but I've replaced it twice. Never did this procedure, never had any issue.

Your argument is with Jaguar's own documentation, not me. I simply pointed to the reference the OP made. Your assertion that it doesn't exist is erroneous. Your assertion that "It used to apply to earlier cars..." is also erroneous. You're certainly welcome to contact Jaguar and argue with them concerning their own instructions on PDI.

enough - let it rest

Happily. I wanted to see that it did exist and apparently it does.

+1 on making a sticky. In Lemreil's case, you would expect a dealership would know of the necessity of this procedure. The fact that they didn't makes me suspicious that it is no longer required on the newer Jags that look more like Hondas.

As dubious as I formerly was about the necessity of performing this procedure, I am now even more dubious that someone who DOES need to perform it will find this thread, titled "Scott" and obtain the necessary information.

Maybe some helpful member will construct a post in the near future detailing the potential problems introduced by disconnecting the battery and their likely solutions, including this procedure? (I can recall reports of radio (that doesn't have security code) no longer working, of course there are well-known park brake and window calibrations, and several who have reported "no crank" and "no start.")

Thanks to Lemriel for posting about this issue and thanks to David for digging up the official Jaguar instructions. Whether or not it's always required, I'm happy to be reminded of it.

As requested, I've made this thread a sticky. I have also revised the title to improve the chances of others finding it. If anyone has a suggestion for improving the title please let me know.

Cheers,

Don

It does also state;

"CAUTION: Before disconnecting the battery, ensure the ignition is turned off for at least 15 seconds. The battery should never be disconnected with the ignition switched on since this will not allow modules to shut down correctly and will result in fault codes being stored and spurious faults being induced.

Ensure a minimum interval of 20 seconds from battery disconnection to battery reconnection. When reconnecting a battery cable, ensure that the operation is carried out in one clean connection to avoid unwanted electrical ‘spikes’ in the system."

This actually makes sense, since many high power devices have "bleeder resistors " across capacitors to slowly discharge to ground. Keeps you from getting a nasty jolt when you work on these circuits, even with power (and battery) disconnected.

hi
just in case any body want's to read the whole doc, I've attached it below
it under the section of "EFFECTS OF BATTERY DISCONNECTION"
out of JTIS
cheers
Joe

https://www.dropbox.com/s/x5ngwxay79...e_pdi.pdf?dl=0