Hello Everyone,

Im new to the forum and also a new Jaguar F-Type R owner MY 2017. I bought the car last August and have had the same issue since purchase.

Issue: The car randomly enters a limp mode while driving. typically when I engage R-Dynamic mode. When scanning the ODB2 codes I receive the following
(Primary) P2138: Throttle/Pedal Position Senor/ switchD/E voltage correlation.
P2138: Throttle/ Pedal position sensor/ Switch D/E Voltage correlation.
P2122: Throttle/ Pedal position sensor/ switch D circuit low input.

The throttle pedal position sensor ( the whole pedal unit has been replaced with a second hand part), Also the connector from the harness into the TPS have been replaced (spliced in by a professional auto mechanic shop here in Michigan) and the same issue occurs.

Background: Jaguar attempted to fix the car and thought that it was fixed (bent pin in the TPS) - car enter limp mode shortly after getting it back home.

Second shop here in Michigan had the car for a full month, spliced in the new connector (from the harness to the TPS) and mentioned that they believe it was corrosion somewhere within the harness and gave up.

Looking for any suggestions as to what maybe causing the low circuit input. Just want to enjoy the car

 

Scary. Which dealer gave up? I usually go to Grand Rapids. The Detroit dealers have a bad rep.

 

So far the car has been to Jag of Novi and Precision Automotive was the last shop to have the car. I am currently looking over the harnesses to see if I can spot any signs of damage.

 

Can you do real time data logging to see what the voltage actually is? Might be a voltage drop due to bad connector, wire or other, but you can confirm that it is a physical issue and not a software/sensor issue.

 

Was just talking to my father, I will invest in a more advance ODB2 reader that will allow me to read the voltage in realtime. Precision Motorsport mentioned that they believed it was something on the Circuit D - pulling power.

I will update you all once I run the live test.

Thanks for the support.

 

Also make sure your battery is fully charged, and isn't too old (is it the original?).

 

I have a Battery Tender that I connect the car to at night. This morning it was indicted the battery was fully charged. Took the car out for some errands. Towards the end of the errands it went into limp mode. - cut the car off and on at the light and it drove home fine.

When I connected the battery to the Battery Tender, the light indicated that it wasn't fully charged. thought that was a bit off- as I only took it on a 10 mile trip a make.

Also purchased the batter new in august- matching specs to the Jaguar OEM battery.

 

Did you reset the BMS when you replaced the battery?

 

I just changed my battery this past weekend.. Advanced said their scanner could not talk to my year car, I have no dealer near me..
what is required to do a BMS reset.

 

I've read that the BMS resets itself eventually, so no need to do anything special, really. That could be wrong, oif course.

 

I wound up buying an Autel MD808P. Looks like AutoZone has them on sale right now. I've also read that the JLR BMS resets itself but I don't trust it. Especially in this case where you're working on electric gremlins.
The MD808 does a couple other maintenance items like put the brakes into maintenance mode, reset service and oil counters and of course reads codes.

 

I picked one of these up - it's bluetooth and uses your phone as the display. It will reset the BMS, parking brake, read and clear DTCs, data log - pretty much everything the stand alone units do, but for $50. It has Jaguar specific downloadable software and auto VIN decoder as well. It's a nice solution without having to drop a lot of money.

https://www.topdon.us/collections/di...oducts/topscan

 

Hello Guys!

Just an update over the past weekend! - Long story Short - Issue not fully fixed but doesn't occur as much !

1. BMS Reset - I fully charged my battery and performed a BMS Reset. I received a limp mode fault directly after performing this. I bought a fox well ODB2 Scanner from Amazon - 20240 model NT726.

2.After the car went into limp mode - I read the codes - same from codes from before. Turned the car off and on and proceeded to take it on a hard drive - and experienced no limp mode faults. I have had the battery on a constant charge every night and haven't had any issues since! So I think this only occurs once the car experience a drop in voltage from the battery - which makes since if there is a bad ground or short circuit.

3. I am sure I have a bad ground somewhere electrically. I ran across this short video on YouTube and performed the test and indeed something is pulling power while the car is completly off- " Power discounted from battery (red positive wire) - .

4.Also ran across a UK form where they speak of the main ground for the car is a junction box poorly located in the right hand passenger front wheel well. It was suggested to check this first as over the years it builds up dirt and corrosion. - https://www.ftypeforums.co.uk/viewto...rrosion#p43081

This seems to be a know common issue on the UK jag forums .

Due to my ODBII code I know I have a short to ground on circuits D/E- this weekend I will pull all fused for components on D/E until the test light goes off- then I will know what component at least is drawing the power even when the car is off! Reading the circuit diagram to know what all is on D/E circuit is hard but I think I can mange

Thank you for the help and suggestions and good luck !

 

I found this unit on a discounted sale on Amazon, out of the box in only showed 2014-2015 F Type in the menu, which was fine as I have a 2015. but after I used it , I did go and do an update on it now it goes up to 2020.
Seems like a decent unit.