Clutch pedal problems

[Black Black]

Hi i wonder can someone advise me on a clutch pedal, when pressing the pedal down to start the car this morning the would not start,its a yaris 2014, then after a while when pressing the pedal after times it started, so I took it to the garage were I bought the car,the mechanic there put some tape over something behind the clutch pedal,and said I could now start the car without pressing the clutch pedal,is that the correct thing to, will what ever he done damage the car in anyway, it works OK now like that.

[Catlover]

Its a safety device such that even if you left the car in gear, but forgot that when you come to restart, the car wont lurch forward and damage something ie another car, a wall, your own car.

What the mechanic has done is tapped down a switch which your clutch pedal would have depressed when you operated the clutch. Tapping down permanantly has negated you pressing the clutch down.  Means that safety feature has in effect been removed.  The other advantage of pressing the clutch down when starting is that it disengages the gearox, thus less drag, less effort required for the starter motor, which is not a bad thing.   

So if you ok with what the mechanic has done, you can still be in the habit of depressing the clutch for safety reasons and also for less effort required from the starter motor. 

[Konrad C]

Adding to Joe's reply, if I am correct, it could be connected to cruise control, if your car has that function. I would get the switch replaced and it's not too expensive - https://www.autodoc.co.uk/car-parts/oem/8452042010

What if the OP's car is involved in a serious crash and the car is examined! Just use this as a temporary fix and get a new part.

[Black Black]

OK thanks both of you for that information, I'll have to think about what konrad said about cruise control and have a word with a mechanic, thanks? 

[Catlover]

Thinking a bit more, and especially after Konrads comments, isolating a safety device so it does not function may be of interest to your insurance company, and you may be better to notify them of the change. There are other threads on this forum of remarks re norifying insurance companies of changes. Insurance companies will be interested because...... if you forget you left the vehicle in gear and do operate the started and damage other property or your own vehicle and a claim is made, they may not be happy paying out if they find you deactivated a safety device.

Thank you Conrad for getting me thinking.

[flash22]

Get the clutch switch changed asap it is a safety device its there for a reason - imo it doesn't need thinking about

[scannerman]

It appears to me that the switch is not defective. What the mechanic has done in taping it down is exactly what the pedal is supposed to do, when pressed all the way down. As the switch prevents the car turning over on the starter when untaped but allows when taped shows that it's working. I would look to see if there is something preventing the clutch pedal fully depressing. I think there is some element of adjustment in the pedal, also make sure you don't have a secondary floor mat under the pedal. IMHO, the mechanic needs beating with one of his spanners, what he's done is a bodge not a fix, if there wasn't a reason for the device to work, it wouldn't be there.

 

[FROSTYBALLS]

The switch, as Catlover said, is intended to prevent the car moving if inadvertently started when in gear. Most cars over the last twelve years or so have been fitted with a similar arrangement.

If you have a driver's floor mat, is this secured to prevent it moving forwards and affecting the pedals? It could be that the mat may have moved and prevented the switch from correctly operating and then after several attempts at starting it may have moved back. Commonly on Toyotas the mats are secured using plastic hooks at the rear of the mat.

 

 

[Tintaglia]

Well I'm with Scannerman on the function of the clutch switch.  If the OP's mechanic physically taped up the switch so that the spring loaded plunger on the switch was held in the compressed position, then the result would be that the clutch pedal would think it was in the 'up' position, ie not being pressed and the car wouldn't start so that would be a pointless bodge.  So something is not quite right here irrespective of hypothetical insurance infringements.

I know this broadens out the original question a bit but regarding cruise control- Pressing the clutch pedal disengages cruise control but this requires that the ECU gets the 'disengage' signal with only the lightest touch on the clutch pedal (before the clutch slips).  Therefore the ECU clearly must 'know' both the up and down positions of the clutch pedal.  Actually I think the functions of the clutch switch are quite a bit deeper than that.  

I wonder what exactly what has been taped?   A good bright torch up under the pedals might reveal all!  

[flash22]

The switches wear (plastic on metal) also the contacts wear and you can end up with a dead spot(s) by taping it up, you push the plunger past its wear points

 

Whether the switch is open or closed depends on the type of switch and the position of the switch, so taping up the plunger will make the circuit (clutch depressed)

The clutch switch may be resistance based or have multiple points,others have a ratchet type mech that positions the plunger these can also fail over time/use,  something I will have to look up

[flash22]

13 hours ago, Tintaglia said:

I know this broadens out the original question a bit but regarding cruise control- Pressing the clutch pedal disengages cruise control but this requires that the ECU gets the 'disengage' signal with only the lightest touch on the clutch pedal (before the clutch slips).  Therefore the ECU clearly must 'know' both the up and down positions of the clutch pedal.  Actually I think the functions of the clutch switch are quite a bit deeper than that. 

If you're changing down gear, you are usually under braking also the ecu will also calculate the engine loading if it's too high it will drop out of cruise, touch the throttle, and it will drop out of cruise

[flash22]

As you can see here it uses 2 switches one for the bottom of the travel and the second for the top of the travel

clutch switch as an example - both switch are the same

https://www.ebay.co.uk/itm/333972093504?epid=28005740759&hash=item4dc249ba40:g:s9MAAOSwLjxggpeZ

[scannerman]

I think you will find that one switch is to allow starting, the other is to restart after stop/start has stopped the engine.

[Tintaglia]

Thanks for the pics Bob, I'd forgotten all about the second switch, dooh!  No stop/start on my 1.33 so the lower switch purely does the 'press the clutch fully down to start' thing and can be easily defeated as happened to the OP.

I still think the ECU uses the other switch to know where the pedal is to improve gearchanges (which it makes a horrible job of).  On VW's, a faulty clutch switch can lead to snatchy gearchanges, and sometimes high idle speed too.  As an experiment, in the past I have tried driving mine with this second switch plunger taped in, and then with the switch removed from the pedal but left connected.  This was all in the past in an effort to improve the well known throttle hanging business.  Oddly enough neither had the desired effect but adding a couple of washers under the switch did as I described here.  It's still not perfect but I'm putting up with it.  One thing I have noticed is that it is tharms.t it improves as the engine which intrigues me.  I still haven't got my Techstream cable working so I can't try and check the coolant sensor or much else. 

Note - The second (upper) clutch switch isn't a safety device!  That's the lower one. 

[Black Black]

Hi all I thought I'd let you know that I've had the clutch switch problem sorted, I've taken it back to the garage, and had the switch put back to its original position, it works now like it should, I was told told that I wasn't pressing the clutch pedal down far enough, and I must admit you do need to press hard to the floor,does anyone else have to this .I've never had to press this hard on any of my past cars.

[flash22]

It's probably still the switch, you shouldn't have to push that hard so it hits the stop - If you can push the clutch down to get it in gear that should be enough to press the switch

It's a 15 min job 1 nut and 1 plug to swap

you could swap the 2 switches over as they are the same part

[Black Black]

OK thanks flash22 I've had that done now,and its a lot better now, its the best thing I've done now is joining this toyota owners club,very knowledgeable chaps on it.

[Catlover]

Hi Peter, I just wondering when you say you have to push down hard, it might be that you seat position means your left leg is at its stretch limit, meaning there is some stretch to actually press all the way down. Just a thought.

[Black Black]

Hi catlover I think your right there, that also improves it a lot better now with new switch and move seat closer.