Polo GTI EPC/Power Loss Issue - help?

[Tobias]

Hello,

Firstly a hello - I'm new to the forum but having a quick read around it looks like the place to post this issue - lots of people out there with much greater knowledge of this sort of thing than me!

I have just been for a drive and noticed a problem I haven't spotted before - loss of power in second gear, coinciding with the EPC light coming on.

The problem occurs after 4000 revs, or thereabout, but seems to only affect 2nd gear. Essentially, a loss of power occurs (foot is still on the accelerator but it feels like it's been removed), and the revs don't climb any higher, and the car does not accelerate any more. Also, at roughly the same time as the power cutting out, the EPC light on the dashboard comes on. It stays on until either I come off the throttle, or change gear. The problem doesn't seem to affect 3rd gear, and I haven't tried in 4th - speed starts to get a bit high at that point. But I'm fairly sure it only affects 2nd gear.

Any ideas, or help, would be massively appreciated.

Info on the car: Polo GTI (1.8T), Y reg (6 years old), (click here for picture of identical car) full service history with no mention of this problem in any other documentation. It recently went in to have an in line fuel filter replaced, and this fault wasn't found or reported by the technicians.

Ideas anyone?

Many thanks in advance.

Toby

[Crasher]

My wife has one, an 07 model. To find out what is wrong you must have a fault code read done but it is likely to just be the brake light switch which is cheap and easy. One thing though, the Polo 9N GTI was introduced in 2005 on the 9N2 facelift (I was at the launch in Germany) and came to the UK in 2006 so it can’t be a real Y reg or 6 years old.

[Tobias]

Hi Crasher, thanks for your reply.

It is going in to have a driveshaft boot replaced in May, so I will ask the garage to carry out a fault code read at the same time. As I said, fortunately the fault isn't apparent during normal driving, nor does it affect my day to day driving. It is slightly concerning though, when it just loses power!

With regard to the fault you've suggested - what exactly is a brake light switch? Glad to hear it should be cheap and easy!

Also, on the age - I think I made erred with the 6 years. It's a 06 plate, so actually only 4 years old.

[Crasher]

A brake light switch is a brake light switch, it switches on the brake lights! What it also does is to send two signals to the engines computer, the signal for the brake lights and a signal sent only to the computer and these have to match, it is a safety system to prevent sudden unintended acceleration of the type that has unfairly and incorrectly blighted Toyotas excellent (and well deserved) reputation. If the two signals do not match exactly, it brings on the EPC light, but it does not necessarily mean the brake lights do not work although I have seen two blown brake light bulbs cause this fault so check they work.

[Tobias]

Thanks again Crasher. I figured the brake light switch must be to switch on the brakes, but it's other functions I did not know, especially how it links to the engine computer. Really useful to know that, and definitely could be what's causing it, given a steady full acceleration might cause the computer issues on that front. Do you think it could be anything else? I guess hard to tell without getting a fault code read done.

Cheers!

[Tobias]

Also, having check the brake lights just now, looks like both are working - so perhaps it's something to do with the computer.

[Crasher]

Not hard to tell, virtually impossible and daft as well, the answer is there by reading the fault codes, fixing it any other way doesn’t make sense. Stop guessing and get it code read, as I said the brake light switch is a dual switch, one circuit powers thee brake lights and sends a signal to the ECU and the other only sends a signal to the ECU, they must match. If the ECU signal is not there but the brake light one is, the lights will work and the ECU will recognise a problem and put on the EPC light, it is extremely unlikely to be anything wrong with the computer, stop fretting and get it code read…