NathR Posted October 10, 2019 Report Share Posted October 10, 2019 Over the past year my cars developed an occasional DPM fault as previously discussed on here... Recently it got to the stage where it was happening on every drive. Thanks to the forum and the above threads I traced it down to the brake light switch. I removed it (without unplugging), pulled the plunger fully in/out then re-fitted it and set it so the brake lights function as expected. For the following two weeks of driving the car everyday (15 mile round trip to work) I didn't have a single issue. 😀 I put this down to a lack of use thing, possibly extending the switch beyond it's normal working range may have cleaned some contacts or something - I have exactly the same problem with the hazard warning switch due to lack of use. Last week the car was in for the 4 year service so I mentioned this and 'self diagnosed' the problem as my dealer wasn't aware of it. Apparently it had recorded a fault code relating to the brake light switch (the MIL light has never come on so not sure if this is true), I was quoted a frankly ridiculous price for the labour to change the switch so opted to just buy the part and fit it myself, which was fine. Then on collecting the car the previous day I was told actually I can't fit the switch as it has to be programmed in by the dealer, does anyone know if there's any truth in this? Given the simplicity of how a brake light switch works I'm surprised by this. 🤨 Quote Link to comment Share on other sites More sharing options...
GFWilliams Posted October 10, 2019 Report Share Posted October 10, 2019 The switch is adjustable, so you need to make sure the adjustment is correct for the position of the pedal. Lotus have access to a lot of stuff with "Tech Centre", including being able to calibrate sensors. I recently had a similar issue, but the brake sensor wasn't the cause, it was actually caused by the steering wheel position sensor. Lotus Silverstone expertly diagnosed and fixed it in about an hour. Quote Link to comment Share on other sites More sharing options...
chumaxa Posted October 10, 2019 Report Share Posted October 10, 2019 It is like 5 or 6 clics out of the switch, I had the same issue, actually bought a new one which would not work fine, so I just changed the setup of the old one .. Quote Link to comment Share on other sites More sharing options...
Hangar 111 Posted October 10, 2019 Report Share Posted October 10, 2019 2 hours ago, NathR said: Then on collecting the car the previous day I was told actually I can't fit the switch as it has to be programmed in by the dealer, does anyone know if there's any truth in this? Given the simplicity of how a brake light switch works I'm surprised by this. 🤨 Hi Nathan. The brake light switch is a two-stage affair, and it should be setup using TechCentre, otherwise you may experience the issue you are experiencing. You might get lucky and it works fine, you might not. Dave Quote Link to comment Share on other sites More sharing options...
RedViper Posted October 10, 2019 Report Share Posted October 10, 2019 I had this exact problem and was paranoid about number of clicks etc but read on another forum to just pull the plunger out all the way and when you fit it into its bracket press the brake pedal in (so it ain’t touching plunger) once it’s in the bracket release brake pedal and let the plunger set itself. I followed that method and it’s been fine for well over a year. I find lotus take the absolute pi$$ with stuff like this. Same as with price of spare parts. Its a shame tech centre isn’t available like vagcom is 1 Quote Link to comment Share on other sites More sharing options...
Hangar 111 Posted October 10, 2019 Report Share Posted October 10, 2019 As I said, you might get lucky, I've seen it work, and I've seen it not work. Nothing to do with taking anything, it's a two stage switch, which must trigger the ECU before the lights. VAGCOM is an aftermarket developed tool. TechCentre is a manufacturer tool. Although only for about two weeks, as it has been replaced by Lotus. Service centres have to pay quite alot of money to Lotus for the diagnostic tools. Dave Quote Link to comment Share on other sites More sharing options...
RedViper Posted October 10, 2019 Report Share Posted October 10, 2019 I just meant it’s a shame the end user can’t do the things you can on tech centre. Vagcom is about £150 I think. I’d pay that for an aftermarket tech centre for my lotus Quote Link to comment Share on other sites More sharing options...
RedViper Posted October 10, 2019 Report Share Posted October 10, 2019 I just looked in service manual and there is a section on things you need to do in Tech Centre. Maybe I was just lucky. I don’t see that you can lose anything by trying it yourself first though. Worst case scenario you lose traction control Quote Link to comment Share on other sites More sharing options...
vd9 Posted October 10, 2019 Report Share Posted October 10, 2019 5 hours ago, GFWilliams said: I recently had a similar issue, but the brake sensor wasn't the cause, it was actually caused by the steering wheel position sensor. Exactly the same for my car Quote Link to comment Share on other sites More sharing options...
NathR Posted October 11, 2019 Author Report Share Posted October 11, 2019 Thanks all for the advice, appreciated. Pretty sure my problem is the brake switch and not the steering sensor given that I seemed to cure it by pressing the switch in further than it would usually operate a few times. I can't see that the 'setting up' of the switch requires anything other than adjusting the plunger so the lights come on with slight pressure to the pedal (as any other brake light switch). However if unplugging it and plugging in a new one potentially upsets the ECU by the sound of it I think I'll leave it as is, the cars now off the road for winter anyhow. If it persists in spring it sounds like a dealer job to swap. Quote Link to comment Share on other sites More sharing options...
Hogi Posted December 20, 2020 Report Share Posted December 20, 2020 My 430 just developed a strange issue. I’ve had the before mentioned brake switch issue bringing on the TC light on the dash. Switch replaced by Bell & Covil. On a drive out yesterday and today I was unable to switch to sport or race. No TC light on dash but definitely no TC available wheels spinning and oversteer everywhere. Any ideas as to what’s happened??? Quote Link to comment Share on other sites More sharing options...
mattsipaq Posted April 15, 2021 Report Share Posted April 15, 2021 Hi, has anyone had this issue after changing the brake light sensor. My dealer swapped out the switch for a new one and the car still throws the Brake Light Sensor error, despite there not being an issue with the switch. They are a bit stumped. Quote Link to comment Share on other sites More sharing options...
Hangar 111 Posted April 15, 2021 Report Share Posted April 15, 2021 1 hour ago, mattsipaq said: Hi, has anyone had this issue after changing the brake light sensor. My dealer swapped out the switch for a new one and the car still throws the Brake Light Sensor error, despite there not being an issue with the switch. They are a bit stumped. Hi Matthew. Ensure your dealer has setup the switch correctly - it's all detailed in the service notes. If you don't get anywhere, I'd be happy to take a look for you. Dave 2 Quote Link to comment Share on other sites More sharing options...
KIMUTAKU Posted August 15, 2021 Report Share Posted August 15, 2021 Looks like this is a common issue. Well, my car just threw the Traction light and ABS light at the same time. Surprise surprise… It went away for a bit then came back on again (both lights). Seems my starting point should be the brake light switch, then steering wheel sensor, then wheel speed sensors as these are all linked to the ABS? Quote Link to comment Share on other sites More sharing options...
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