430 Cup, intermittent TC light + dangerous power cut

[mr_wyn]

Hi all, I seem to be having some issues with my 430cup, its only done 3k miles. 

I am getting a TC error/fault message that randomly comes in, it seems to clear when I turn the car off and back on (with they key out) I suspect it could be a brake sensor issue? 

The more dangerous thing is recently it randomly just loses all power whilst just cruising, no response on the throttle whatsoever, I drove on the A1 whilst overtaking a lorry and all power was completely out, restarted the car as it was rolling but I had to pull over whilst it was decelerating, it didnt feel like a fuel cut out (whilst pressing the throttle) there was simply just no response, it was an extremely dangerous experience for me as there were cars around and I only managed to squeeze into a very slim hard shoulder. Stopped the car, took the key out and restarted and everything was normal... I do no wish to drive the car with this issue, can someone perhaps shed some light if you've had a similar experience? would be immeasurably appreciated, thank you.

[Seriouslylotus]

Sounds like the brake light switch that needs either correctly adjusting or replacing and correctly adjusting.

[mr_wyn]

5 hours ago, Seriouslylotus said:

Sounds like the brake light switch that needs either correctly adjusting or replacing and correctly adjusting.

I had the feeling after spending some hours researching, however I didn't find anyone with a complete power cut in addition to the problem, I will adjust and reinstall the switch and also buy a new one. Do you have any additional details to share / to look out for? much appreciated thank you

[Jcx]

I had the same behaviour on my 350 sport when new. Brake sensor switch was replaced and it never happened again. Good luck. 

[mr_wyn]

5 hours ago, Jcx said:

I had the same behaviour on my 350 sport when new. Brake sensor switch was replaced and it never happened again. Good luck. 

Thank you, I ordered a new part - did you also experience the total power loss?

[Jcx]

5 minutes ago, mr_wyn said:

Thank you, I ordered a new part - did you also experience the total power loss?

Yes i did a number of times.  was very unnerving.  Turns out these switches are very temperamental especially if you have tried to heel and toe - as i was told.  They can cut power to the engine if the switch senses pressure on the brake.  Not good for H&T.  Also, they can quickly move out of tune to cause the total power loss.  Happened on my new (130 mile) exige 350.  Lotus were epic about it.  Both Central Lotus (supplying dealer) in Nottingham and Lotus HQ/Warranty team were on it like flies and had the car back and sorted in a flash.

[mr_wyn]

46 minutes ago, Jcx said:

Yes i did a number of times.  was very unnerving.  Turns out these switches are very temperamental especially if you have tried to heel and toe - as i was told.  They can cut power to the engine if the switch senses pressure on the brake.  Not good for H&T.  Also, they can quickly move out of tune to cause the total power loss.  Happened on my new (130 mile) exige 350.  Lotus were epic about it.  Both Central Lotus (supplying dealer) in Nottingham and Lotus HQ/Warranty team were on it like flies and had the car back and sorted in a flash.

Thank you for clearing that up for me! puts my mind more at ease with it being just the switch. I am not surprised about Lotus either, as an OEM they really should issue a recall on this and adapt a newer and more modern part, its severely dangerous

[mr_wyn]

Hi Guys, replaced my sensor but the problem still exists, and even more now than it did with the TC light coming on almost immediately - I've ordered another part so I'll see how this goes, any suggestions to what else it can be?

[Hangar 111]

4 minutes ago, mr_wyn said:

Hi Guys, replaced my sensor but the problem still exists, and even more now than it did with the TC light coming on almost immediately - I've ordered another part so I'll see how this goes, any suggestions to what else it can be?

Does it come on with the first press of the brake pedal?  If so, you've not setup the sensor correctly.  A search will find you the answer to your next question...

Dave

[mr_wyn]

30 minutes ago, Hangar 111 said:

Does it come on with the first press of the brake pedal?  If so, you've not setup the sensor correctly.  A search will find you the answer to your next question...

Dave

Thanks Dave, I will get under again and see, I've followed the instructions from all over the web, adjusting the plunger etc, sensitivity for the brake light seems good (something like 1-2mm depress lights come on) last resort was to make a thread on here to see if there are some recent experiences with the issue

[Hangar 111]

10 minutes ago, mr_wyn said:

sensitivity for the brake light seems good (something like 1-2mm depress lights come on)

This is probably your problem.  As I've said many times, it is a two action switch, and to set it up properly you need to be using the diagnostic tool - anything else is fluke.

Dave

[GFWilliams]

I had the traction light come on a while ago and it was caused by the steering wheel position sensor. Need Lotus diagnostic tool to find out and reset it. It can be quite a few different things, but the brake pedal sensor is most commonly talked about.

[mr_wyn]

Can indeed confirm its the brake sensor with some adjustments, everything is working properly now, but waiting on a new switch just to be sure

[mr_wyn]

Just to additionally add my input and experience :

TC light would almost come on immediately 5 mins into the drive. I bought a new switch and replaced it and it was a total DUD, replaced it back with the old one. Pulling the plunger in and out a few times initiating the ratchet mechanism. I set it for 6 clicks, though I recall the manual says 5, but 6 works well for me. 

I did all of of this with the car off and key out when plugging back in the part. Locked the car, and waited a few minutes, turned it on and after driving roughly about 30 miles in the last couple of days everything seems to be fine and no lights - Waiting on a brand new sensor to install just incase, I remember when my car just completely cuts out I don't recall seeing the TC light on the dash or any symbols, so this requires some time to see if it will do it again and whether or not its a completely separate problem which I am hoping its not. 

Also as its quite a primitive and mechanical machine its not really hard to take apart, I've taken apart many cars in my time - all the sensors and wiring components are quite generic and easy to undo. Used the OBD2 dongle and a couple of apps to clear any codes to make sure there's nothing bugging the ECU. 

 

 

[Jcx]

fingers crossed Mister.

[mr_wyn]

Update to provide reference for those in the future who may come across the problem - The car is again working flawlessly, eventually I just pulled the plunger of the new sensor out as long as it can go (as I wasn't happy with the brake light sensitivity with my initial attempts) fixed the unit back into position, released the brake pedal and allowed it to set it was the easiest for me, no TC light, no engine cutting, I've done around 1000 miles (long and boring drives for meetings) so since then, loving every moment of it! 

[MrD]

 

Bringing this thread back to life:)

I had the TC issue 2 years ago and a new sensor fixed it. I simply installed the new item without adjusting as at the time I was not aware of it.

However I got the TC on again today and car on limp mode (EML switched on). Got another one on order but what is the best way to adjust prior to fitting please? I read about 5-6 clicks and/or a lotus tool. @mr_wynhave you got any further issues after installing yours in the way you did?

Thanks 

[390ja]

Just to add something I didn’t see covered in this thread.

I had this same issue recently.

I put esp fully off and it made mine drivable without the constant power interruptions. Enough to drive comfortably to the dealer at least.

[cuprapw]

When I did it, it was 6 clicks for me (from fully retracted). Just check with 5/6 clicks what the brake pedal travel is when you can see the brake lights come on.

Another good reference is (if you have it) when it kicks you out of cruise control. In my case, with 5 clicks, just the slightest touch on the brake pedal was kicking me out of CC.

[Troyboy]

On 14/08/2022 at 09:12, 390ja said:

Just to add something I didn’t see covered in this thread.

I had this same issue recently.

I put esp fully off and it made mine drivable without the constant power interruptions. Enough to drive comfortably to the dealer at least.

The TC light has just started to come on with my 350 Sport. It took about 25 miles before it came on last Friday. As said switching off and waiting a minute clears it but only for about a further 10 miles then it's back on. No loss of power. I am switching race mode on until it gets serviced to see if it has any effect. My car hasn't been driven hard at all. No track time. It has only 4600 miles and is exactly 3 yrs old. Its all very good putting new brake sensors on the car but how long will they last. 

[390ja]

Mine was only just over a year old with about 6k miles on. No track time but I gave it a fair bit of stick at times.
Race mode itself still played up and cut power, I had to re-press and hold to fully deactivate traction control to make it drivable.

[Troyboy]

The disappointment for me is these problems shouldn't be arising on such young cars. I bet the same will arise on the new Emira. Poor quality parts as per usual. 

 

[390ja]

At least they have shaken the “S” off the age old acronym..

[Troyboy]

Fair point.

[Dark]

I had the same issue during a trip to France with LOT last month.

First time it lost all power after driving across a tram track. Turning off/on didn't fix it but after pumping the brakes the throttle came back. It did it again twice on track the next day, seemed to occur after touching a curb on a trailing throttle.  After clearing the 2nd occurrence the TC light came on and the rest of the day was uneventful although without TC. Same then occurred everyday on track and on road.

As a temporary fix I adjusted the brake pedal switch by moving one click in so the lights came on earlier, it left the TC light permanently on but no more power cuts. New switch installed and setup by CMC today and issue seems to be fixed.

For info car is 4 years old and 8k miles.

Edited September 7, 2022 by Dark