Bob Lemay Posted March 24 Report Share Posted March 24 Hello Everyone, I've been noticing some complete throttle shutdown, maybe a second or two, then it's restored. I keep thinking my foot is coming off the petal, but tonight, I confirmed by looking down at the accelerator as it was happening. Definite cutout. Anyone ever experience this? Thanks in advance Bob, 2005 Boxster S 987.1 Quote Link to comment Share on other sites More sharing options...
Menoporsche Posted March 25 Report Share Posted March 25 Cold or warm engine? Quote Link to comment Share on other sites More sharing options...
iborguk Posted March 25 Report Share Posted March 25 (edited) Any codes logged ? Brake or clutch pedal switch ? Throttle pedal assembly ? Throttle position sensor ? Throttle body ? AOS ? Edited March 25 by iborguk Quote Link to comment Share on other sites More sharing options...
Boxa Steve Posted March 25 Report Share Posted March 25 Hi Bob. This happened to my 987.1 3.2 S and the cause was a faulty brake pedal switch which at the time seemed hard to believe as you wouldn't think they are connected !! Quote Link to comment Share on other sites More sharing options...
Bob Lemay Posted March 25 Author Report Share Posted March 25 Warm engine, I guess the only way to check the switches is to replace them? Quote Link to comment Share on other sites More sharing options...
Boxa Steve Posted March 25 Report Share Posted March 25 Yes warm engine happened when you went to pull away, most disconcerting ! Hasten to add it was intermittent. Quote Link to comment Share on other sites More sharing options...
Paul P Posted March 25 Report Share Posted March 25 Heard of brake light switch causing this a few times. Not definitive of course but pretty cheap 1st attempt I would say. there’s a chance that a decent code reader with live values would “catch” the situation - or there may be some “implausible” conditions logged so it’s worth a quick check if you have access to a reader but I don’t have high hopes. Quote Link to comment Share on other sites More sharing options...
½cwt Posted March 25 Report Share Posted March 25 10 hours ago, BoXa Steve said: Hi Bob. This happened to my 987.1 3.2 S and the cause was a faulty brake pedal switch which at the time seemed hard to believe as you wouldn't think they are connected !! They are connects in most electronic throttle cars to prevent the driver from applying power whist also braking. Quote Link to comment Share on other sites More sharing options...
Bob Lemay Posted March 25 Author Report Share Posted March 25 Ok, well just arrived home and squeezed down there at the switches, a feat in and of itself, and inspected the switches. Nothing looking out of the ordinary, but you can't see a faulty switch. I guess the next order of business would be to order a new brake switch, not a very expensive purchase. I'll take it for another nightly drive tonight and see what happens. Quote Link to comment Share on other sites More sharing options...
Freeman Posted March 25 Report Share Posted March 25 20 hours ago, Bob Lemay said: Hello Everyone, I've been noticing some complete throttle shutdown, maybe a second or two, then it's restored. I keep thinking my foot is coming off the petal, but tonight, I confirmed by looking down at the accelerator as it was happening. Definite cutout. Anyone ever experience this? Thanks in advance Bob, 2005 Boxster S 987.1 Yes, still checking for possibilities. My throttle box was replaced but didn't make any difference. The brake switch was replaced and all connectors on the ECU were cleaned. I have managed to drive the car X2 and had no issues. Quote Link to comment Share on other sites More sharing options...
kevin450 Posted March 26 Report Share Posted March 26 I’ve had the same problem 2005 3.2s triptronic intermittent loss of throttle changed the brake switch solved my problem it’s a cheap go at fixing the problem I had no brake light problems just note the way you twist the switch to remove to refit switch it’s a bit awkward 😬 Quote Link to comment Share on other sites More sharing options...
Ninesomething Posted March 27 Report Share Posted March 27 Brake light switch - betcha. The ECU won't let you accelerate and brake at the same time as you'll know if you've ever tried to left foot brake. As the switch fails it sends the wrong signal to the ecu which cuts the throttle. If you back off and get straight back on it the power comes back. Easy fix. Quote Link to comment Share on other sites More sharing options...
Bob Lemay Posted March 30 Author Report Share Posted March 30 Well, It was a $20 fix! One brake light switch, and a can of electronics cleaner..not one incident in tonight's 2 hr. ride. A bit of dielectric grease on the switch tabs, and a spray of cleaner on the ECU connectors! Hardest part is getting to the switch, I ended up taking the seat out for easier access. Thanks so much for the info!! Bob 3 Quote Link to comment Share on other sites More sharing options...
EXY Posted March 30 Report Share Posted March 30 17 hours ago, Bob Lemay said: Well, It was a $20 fix! One brake light switch, and a can of electronics cleaner..not one incident in tonight's 2 hr. ride. A bit of dielectric grease on the switch tabs, and a spray of cleaner on the ECU connectors! Hardest part is getting to the switch, I ended up taking the seat out for easier access. Thanks so much for the info!! Bob Here's a handy tip,,,, WD40 is excellent at dissolving oxidisation on contacts if you don't have access to some solvent based Switch Cleaner of course. Quote Link to comment Share on other sites More sharing options...
Bob Lemay Posted March 30 Author Report Share Posted March 30 Very Good! Thanks for all the tips, I would have never of guessed that the brake light switch would have been the culprit here, my mind's diagnosis went right to what ever kind of servo, or mechanism opens and closes the throttle body's plate. Glad I didn't have to mess with that. The old switch that I removed was completely shot, the plunger barely able to return to open position. Brake lights still worked, but the cut out was just getting worse and worse. Thanks again, Bob Quote Link to comment Share on other sites More sharing options...
Ninesomething Posted March 31 Report Share Posted March 31 14 hours ago, Bob Lemay said: Very Good! Thanks for all the tips, I would have never of guessed that the brake light switch would have been the culprit here, my mind's diagnosis went right to what ever kind of servo, or mechanism opens and closes the throttle body's plate. Glad I didn't have to mess with that. The old switch that I removed was completely shot, the plunger barely able to return to open position. Brake lights still worked, but the cut out was just getting worse and worse. Thanks again, Bob That's the thing - seems to cause the throttle issue was before it ever stops the brake lights working. Which I suppose is a good thing in a way. Porsche's coded message to tell you there's a problem before some idiot rear ends you. 🙄 Quote Link to comment Share on other sites More sharing options...
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