Hey all! I'm a relative newbie here and to owning a Jaguar / luxury performance vehicle in general. I bought my '16 AWD R about 2.5 years ago. I've been plagued by the Restricted Performance mode on several occasions (including at the drag strip two summers ago, that ~48 second 1/4 mile was a memorable one, and I genuinely plan to frame the slip), but it's always intermittent. I did manage to get it scanned and when I looked up the code it was related to the Throttle Position Sensor. It's my first fly-by-wire vehicle, and unfortunately, my experience w/ that system has been abysmal. It goes through periods where it surges at partial throttle, and that's usually a clear-cut sign it's about go into limp mode. I can also trigger it sometimes by just revving at idle -- any fast change in throttle position will often trigger it (that's not the least bit embarrassing when you're trying to rev for somebody upon request, btw ), so I'm reasonably sure that's the problem.

My local dealership has been less than stelar w/ trying to get service. IIRC, they said I couldn't order the part through them because they wouldn't hold that item, and they'd only order it and replace it through their service dept. When I brought it in, of course I couldn't get it to go into Restricted Performance mode, and they looked at me like they couldn't do anything about it to try to trigger it despite me telling them what causes it. Can they not rev the vehicle or drive it hard? Maybe company policy, idk? The estimate for them to do the diagnostics and potentially replace the part was outrageous anyway, so I decided to try and do the work myself. I thought I found the right part on e-bay but the cable pins don't align and, while the general appearance of the part matches pretty closely, the port for the plug is in a different location, ~90 degrees away from where mine is. It wasn't much (<$40 iirc) but now I'm trying to track down the exact right part, so I don't inadvertently expand my collection of Jaguar gas pedals. If somebody can point me in the right direction? Maybe I should try another dealership? I feel like a fish out of water dealing with them. Any help appreciated. Go easy on me pls!

 

Codes always codes!
Without someplace to start we have no idea what to do?
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Fair enough. It's in getting the oil changed right now. I remember it saying "Accelerator Pedal Position" in the code description when I looked it up, so maybe "Throttle Position Sensor" is not the right description. P1576 sounds familiar, but I will scan it at O'Reilly's on the way home from the shop (assuming I can trigger limp mode).

 

Okay, just scanned it. P2122 and P013E showed on the scanner from the history. I'm guessing P2122 is the culprit for my intermittent limp mode? The other looks related to O2 sensor stuffs.

 

FYI…
https://www.jaguarforums.com/forum/f...erator-283673/

 

That's my post on this topic, above. I went through the same issues. Your code is an out-of-range reading for the low throttle position. You can clear this code with any reader, and it will wipe the limp mode that this code imparts. After that, you want to find the source. First thing is make sure you have a fully charged battery. I had to replace my battery, and this helped. That may be all you need. If not, well, read on....

Second, you can try another accelerator pedal assembly (they're cheap on eBay). In my case, this actually made the problem worse (see my post, above, for details).

My third attempt at a fix is something that's worked great so far. I haven't reported this fix yet, as I'm gathering more time to see if this is truly a permanent fix. With about 20 hours on the car, I haven't had the code return. Previously, I would get this same code roughly every 4-6 hours.

So what's the fix? I installed a throttle controller. This is a box that goes between the throttle pedal and the ECU. It remaps your throttle curve to give more sporty performance. I ordered the unit from Jag Madness, and also spoke with their lead tech about using this to fix throttle codes on the F-Type. He thought that was an excellent idea, and I got a bit of technical info about these boxes that gave me more confidence that this fix might work.

These boxes auto-calibrate and then send the appropriate signals to the ECU. They independently read the accelerator pedal position, then take care of sending the proper signals to the Jag. This is way-more complex than you'd think, as the Jag has a redundant circuit that needs TWO separate voltages, one exactly 1/2 the magnitude of the other, to tell the ECU the pedal position. Any variance in these independent circuits, and the car will throw throttle codes.

These pedal-commander boxes basically spoof these redundant signals and send the correct voltages to the ECU. My thought was these might also cure some of these throttle codes in our F Types, and so far, that's been the case. It's still a bit early to declare victory, but I'm very pleased with the lack of codes so far.

On final bonus of these boxes is they make the car far more exciting to drive. Really. You'd think a simple throttle remap would be a ho-hum upgrade, no big deal. Actually, it makes the car feel much more agile. Hard to describe, you just have to try it. VERY very happy with that element of this fix/upgrade.

So, please excuse the long description. I've been meaning to write-up this fix and put it in my thread, but your posting of the same problem prompted my to just reply here. FYI.

Good luck.

 

I forgot to mention, if you do decide to order the Jag Madness Pedal Controller, I'd recommend the bluetooth version. This comes with a small (wireless) bluetooth "puck" to control the unit. I keep mine in the center cubby. Eliminates all wires. FYI.

https://jagmadness.com/index.php?rou...ct_id=33115590

 

Thanks for sharing your experience, and hopefully that fix is permanent for you this time! If I was going to keep it for myself I might think about that (and an underdrive pulley, lower air box, tune, etc.). I'm after the stock appearance and behavior though. Unfortunately, I'm going to have to unload her once I make sure it's solid enough for me to feel comfortable selling. I don't know if the new owner is going to be thrilled with filling up the one small cubby space in the cab with a puck to broadcast the % throttle.

Is 46 too early to start saying things like "I remember when throttle-bodies and blades didn't require computers and electronics to open and close"? I get there are theoretical advantages to fly-by-wire, but this kinda sucks. Limp mode is flat out dangerous on the road. I was on a 55 mph highway when it kicked in this last weekend sitting at a red light. It took me a good 50+ seconds to get up to speed. 0-10 is pretty quick, but then it is ludicrously slow getting up to 50+, you wouldn't even know I was on the throttle. When you do finally get up to speed and let off you don't feel any change in acceleration. I had a cement truck tailgating me ready to run me over the whole time, at least until he went around me.

 

The puck is tiny. Just a bit bigger than a US quarter. And, you don't have to keep the puck with the car. It's used only to change settings (or you can use your phone with an app). You could install it, and forget all about it, honestly. If this does resolve the (relatively common) Jaguar throttle codes, it's worth it for that alone. Others have been chasing these issues for years, with a few horror stories (replacing entire wiring harnesses and ECUs and still no resolution...)

 

Great post and info diablo2112! I learned something today for sure!
It's amazing what you can find with the actual trouble code. That's why I sound like a broken record and keep asking for codes. Without codes we are all just flying blind.

I have heard about pedal controllers before but have no experience. Do you think the car is faster now compared to stock?
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There's no way the car is faster. This mod adds zero performance gains. With that said, hell yes! It feels like an entirely different vehicle. As I said, you simply have to try the car with and without to appreciate the difference.

Now, a bit of sad news. The car threw a code today, same one (low throttle input error). Interestingly, limp mode wasn't nearly as incapacitating with the pedal commander box installed. I had a decent amount of power, and was able to move the car to a safe spot pretty easily.
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Now, onto attempt 4 at a fix. With the commander box, I can rule out anything on the pedal side of things. These leaves the throttle body. I found a bit of good info in the repair manual. Here's the relevant text:

"The throttle plate is operated by an electric DC (Direct Current) motor integrated into the throttle body. The ECM uses a PWM (Pulse Width Modulation) signal to control the DC motor. The ECM compares the APP sensor inputs against an electronic request or value to determine the required position of the throttle plate. The ECM and electric throttle are also required to:- Monitor requests for speed control operation.
- Automatically operate the electric throttle for accurate speed control.
- Perform all DSC (dynamic stability control) engine interventions.
- Monitor and carry out maximum engine speed and road speed cut outs.
- Provide different engine maps for the ride and handling optimization system.

A software strategy within the ECM calibrates the position of the throttle plate at the beginning of each ignition cycle. When the ignition is turned on, the ECM performs a self-test and calibration routine by fully closing the throttle plate and then opening it again. This tests the default position springs and allows the ECM to learn the fully closed position."

This last bit is the relevant part. It's my guess that the low-input error is now related to the ECM calibration of the throttle plate. If it gets different values before and after actuating the motor, it returns the P2127 code. My next attempt at a fix is to replace the throttle body. I've got one on order now and will report back if this works.

Stay tuned.

P.S. I also have a theory as to why I got less-frequent codes with the commander box. If this is a throttle body motor/spring calibration issue, it's possible the commander box excercises the throttle motor more vigorously. This may help with whatever spring/zero-point/calibration issue I'm having. This at least sounds plausible to me. These occasional Jag issues make a fine puzzle, don't they?

 

Ah, bummer! Hopefully your ongoing investigation and journey yields better results.

I was going to take the Jag out to take pics for when I put it up for sale, but was greeted by a dead battery this morning. I suspect the OBD II scan at the auto-parts store yesterday left it in some stupid mode that caused the battery to drain overnight. At any rate, hours of charging didn't give me enough juice to start it, only enough to pop the trunk so I could remove the battery. I took the dead battery to the same auto-parts store (they confirmed it was dead-dead) and bought a new one. After installation, so far so good, but it's still early. I don't drive much, so I don't know how long or how many short trips to give it before declaring victory. As I'm sure you know, this sucks! heh

 

Battery is indeed the very first thing to check with electrical issues. As you've learned, there's a bug in the OBD ports on (some) cars. After using a reader, the OBD port keeps something in the electronics in a state of constant-on that drains the battery. Solution is disconnect the battery after using the OBD reader. I keep a 13mm socket wrench in my trunk for this. FYI.

 

You MUST fully charge the battery! New batteries are not fully charged. An insufficient charge can produce odd and varied symptoms in the module systems. In reading your thread, the very first thing that came to my mind was insufficient battery voltage. While I hope you have not unnecessarily spent time, money and effort trying to solve this issue, I would not be surprised if a fully charged new battery were to be the fix. Then you could keep the car😀

 

Thank you both for driving home the message. I hear you and I get it, now. Honestly, I'm probably not the right owner for this kind of car. I work from home. I've got a stay-at-home wife and two kids (a toddler being one of them, totally unplanned and naturally just months after buying this car). My driving consists of driving my older kid ~2-3 miles each way to and from school. The Jag is obviously a luxury, and somewhat of a garage queen. We have 4 (!!!) vehicles. The challenge as a work-from-home person w/ kids is trying to keep all the batteries from not going dead just sitting around for days, weeks, sometimes months on end. This car, with its extreme intolerance for any variation in voltage, might just be a terrible (too strong?) fit for someone who seems always on the cusp of a dead battery, times multiple vehicles.

When this car and everything in it are working in harmony, she's a thing of beauty, and she has that streak of downright nastiness in her (in a good way!), when you want it. Elegance and grit -- the sounds that come out of her don't sound like they should be coming out of her, and I love it! In addition to this bizarre (to me) challenge with maintaining the battery, I'm at the tail-end of a solo project I'm working on and we're at the end of our runway as far as finances go. I could barely justify having two fun cars (I still have my Trans Am, yes, dead battery and all) when we were sitting on more money / runway early in this project, and that was before the second child entered the picture. The Jag is the obvious choice to be on the chopping block.

I'll be sad to see her go, but hopefully she'll find somebody who can treat her right.

 

Eliminating battery worries is so simple: you permanently fit a CTEK battery minder (or similar) and keep it plugged in (a 3 second task) when the car is not in use. This guarantees a fully charged battery always - and the result is the elimination of module starvation!

 

It kind of begs the question -- why did they _not_ install something like this from the factory? Maybe along with some kind of dash indicator to notify the owner/operator when the voltages aren't exactly where they need to be? Perhaps slightly more important than being incessantly warned my left rear tire is half a pound too low on pressure when it's cold out in the morning? Instead let's throw a bunch of cryptic codes and put the car in limp mode for some extra fun and drive the owners crazy trying to diagnose and troubleshoot all these symptoms and red herrings so they can throw thousands of dollars at that, when all along it probably just needed a battery at 100%?

Like I said, if I was going to keep the car I'd do this in a heartbeat and I'll probably mention this advice to whoever buys the car. "Look, you're essentially getting a gas-guzzling EV with a really badass exhaust note. Just plug it in every night and keep the battery charged at all times!"

 

This isn’t a “Jaguar thing”. The issue of full battery voltage for modern cars (especially those that may not be used daily) is so essential that EVERY luxury car manufacturer sells the CTEK units under their own label - every one, from Bentley and Bugatti, Lamborghini and Maserati and Ferrari, and yes, Jaguar and Land Rover, Mercedes, Audi, Rolls Royce…). And Jaguar also has an installation kit for the maintainer which provides a permanent plug-in location in the trunk.
A few of the more expensive cars do come with the CTEK unit from the factory.

 

Plus every Jaguar/Land Rover dealer I have ever been in has all the cars on the show room floor hooked up to CTEK's.
That kind of said it all for me!
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Maybe they're just getting Jaguar owners used to the idea of plugging in their vehicles every night, in preparation for their all electric lineup.