brake_light_switch_replacement_smart_fortwo_451_not_selecting_gears¶

3 excerpts.

Excerpt¶

youtube.com/auto_knight/brake_light_switch_replacement_smart_fortwo_451_not_selecting_gears · p. 1 · Applies to: 450, 451, 452, 453, 454, #1, ebike

hello and a very one welcome to another video from Auto night now when I got back from my Christmas and New Year holiday in California I decided it would be good to give the smart a drive because it hadn't been driven for weeks now to my horror when I got in it I couldn't select any gears it just stayed in neutral with flashing n so in this video I'm going to take you through the process of diagnosing this fault you'll probably tell from the thumbnail what it actually turned out to be but it's good to understand the process in getting there [Music] [Applause] okay so start the car C on brake select reverse and nothing on the dash just flashing in now you will also note that I've got the hazard light on there and also the ABS light the exclamation mark that's just a handbrake I can put that one out so we have an issue now the first thing that crosses my mind is the fact that to select gears depends upon there being a signal from the brake light switch so my first thing to check is have we got brake lights let's see if we've got brake lights that's definite no so next it makes sense to check the fuse for the brake light circuit it's actually fuse number 24 which is this one here 15 amp blue I'll just run a continuity check on that fuse and you can hear that that's fine now to me the next logical step is to move towards the brake light switch now fortunately I've already ordered one this was about 16 quid from Smart tune it's a little bit difficult to access which we'll now demonstrate the brake light switch on these cars is not the most ideally Loc ated it lives under the vehicle so we need to get to it from underneath which will involve removing the front under tray section the car is supported on axle stands at the front the handbrake is on and the rear wheel is chocked I'm using some of my favorite bedding to protect me from the ground I can have that cleaned and back on the bed by tonight and this front section needs to be removed looking at this it seems that much of it is actually held on with cable tires so something's obviously happened here in the past there are a series of 10 mil bolts that need to be removed I don't think this front section is actually meant to be in two pieces I think it's just broken and that's why we've got the cable tires but I'm going to undo all these various bolts the front's just front just unclips like that got another cable Tire here at the front that's definitely not meant to be there can also see some glue from a glue gun here another cable tie here I'm sensing a theme developing just in each front wheel Arch here there's this bolt to undo again 10 mil and the same on the other side got a plastic nut in each of these recesses as well again it's 10 mil it's missing from this side for some reason fact the stud isn't even there another bolt here and then this section can be [Music] lowered the box that houses the brake light switch is up under here and it's going to be easier if we remove this plastic cover as well in order to gain access this is held on by a couple of 10 mil plastic nuts they're quite close together in the middle this has a little hinged section here in the middle so it's kind of two pieces very hard to

Excerpt¶

youtube.com/auto_knight/brake_light_switch_replacement_smart_fortwo_451_not_selecting_gears · p. 2 · Applies to: 450, 451, 452, 453, 454, #1, ebike

demonstrate but you hinge this piece around which enables you to get it past these two airon pipes quite well designed in that sense if not we wouldn't be able to get this out of the way this now gives us really good access to the plastic box where the linkage for the brake pedal and the brake light switch live so we pull this clip here at the back which releases a couple of lugs and then we remove this cover from the car which reveals the brake pedal linkage where it goes into the servo over here and the brake light switch when the brake pedal is not being pressed pressure is on the switch so for that reason I need to apply some pressure to the brake pedal so we can remove the switch I've just placed breaker bar between the seat and the pedal to apply pressure to it you'll now see there is a clearance between this linkage and the switch so it's no longer under any tension and now it is just a case of push and twist and it's removed now I just disconnect this electrical connection here so this just disconnects it's very tight it's quite hard to remove and then the switch pushed back in and twisted fully home there was a little click there now time to release the brake pedal brake pedal is released and it's just pulled back as far as we can which just sets the new Switch and before I put all of this back together now is a really good time to check to see if we have indeed got brake lights and indeed we have outstanding so before we start putting things back together water Ingress can be a problem for this now the very fact that it's got one of these little one-way drain valves here would suggest that water is meant to just exit should it get in there at the lowest point I can see that's bone dry in there I mean there's even dust so I don't think water Ingress has been a problem here at all so I think that uh switch died of just component failure natural causes as people say um I don't think it was ruined by water uh this seal here still looks flexible and I think that will go again uh so I'm not going to go put in loads of guns around that I'm just going to refit that as it is had this been soaking wet in there I may have taken a different view on that so while in here I think it's probably a good opportunity to just lubricate this forrum [Music] here with some white grease I don't really want to have to take this all apart again if it ever developed a squeak just checking that this mating surface is good which it is and now refit the cover two slots at this end and it snaps back together at the back end again I checked earlier but it's important to make sure this little drain valve thing this oneway drain valve is clear in case water should ever get in there it's also interesting to note that I haven't seen a single bit of corrosion anywhere under here which is really good to see when now refit this over the air conditioning pipes relocate this under tray between the body of the car and the wheel opch liner so it sits flush just tightening the center bolt to keep everything in position with the exception of the plastic nuts all these self-tapping bolts are actually the same length so you don't have to worry about what goes where and obviously my car has the added luxury of these cable ties because this part of the engine under tray which is off the car should actually be uh attached permanently to the part that's on the car but it's obviously broken off but it's not a massive problem it's just an undertray and finally the front section of the under tray is reattached [Music]

Excerpt¶

youtube.com/auto_knight/brake_light_switch_replacement_smart_fortwo_451_not_selecting_gears · p. 3 · Applies to: 450, 451, 452, 453, 454, #1, ebike

cable tires have their uses this isn't really my style but I'm not too worried about it as it's only the front section of an undertray that is all refitted back in the car let's see how this is now behaving put on the brake let's go for reverse excellent neutral first auto back to neutral reverse I think we can safely say that's fixed so just out for a little road test and um both warning lights are out which is great gear changes are fine and it's selecting gears totally normally very successful repair so if you ever find that you cannot select gears on you're are smart for two 450 or 451 this could be an important thing to check we used to go spending lots of money with a dealership hope you enjoyed the video lots more to come please do like and subscribe dangerously close to 1,000 subscribers now please help me make that happen I'll see you in another video soon thank you and goodbye