I've had running problems with the car before.

Suttery performance - not fixed

http://briskoda.net/forums/topic/168529-a-million-fault-codes-vrs-mk1-oct/page__p__2049921__fromsearch__1entry2049921

A million fault codes

http://briskoda.net/forums/topic/148902-vrs-hesitant-on-light-throttle/page__p__1857947__fromsearch__1entry1857947

Now the car is throwing up EPC, Traction Control Warning Lights and The Light In The Shape Of An Engine many times a journey.

It seems to be as the boost is building, the boost will just suddenly go and the lights will come on. I regularly stop to undo the negative terminal of the battery to clear codes - but The Light In The Shape Of An Engine has remained.

Another symptom is that problems are more frequent when starting first thing on a cold morning. It also really snaps the throttle shut when lifting off on the throttle after a bit of acceleration on boost, which makes driving smoothly almost impossible

you need to get the fault codes, then people will be able to help mate

you need to get the fault codes, then people will be able to help mate

I can't right now as am at work.

I'm pretty sure that the list of codes will be similar to the 'million fault codes' link - though there might be one or two extra as the The Light in the Shape of an Engine has never been lit before.

I'll post up the codes when and IF I get home, but right now I'm really hoping for someone to recognize the symptons. Perhaps I can get the bits ordered from the local dealer this morning and fit this afternoon or evening...

I bet there will be a 17705 code in there somewhere, you could be losing air from somewhere. Time to get dirty :wonder:

I bet there will be a 17705 code in there somewhere, you could be losing air from somewhere. Time to get dirty :wonder:

There was previously - see : http://briskoda.net/...1entry1857947

I had a right good look around the suggested areas (check out the photys in that link). There was nothing obvious - perhaps its leaking from somewhere less obvious

One thing I noticed when cleaning the Throttle Body (months ago) was that the butterfly seemed to keep changing its mind slightly about what angle it should be. - even though the throttle was a consistent position.

This was when I had a brick on the throttle to hold it open - for cleaning.

One thing I noticed when cleaning the Throttle Body (months ago) was that the butterfly seemed to keep changing its mind slightly about what angle it should be. - even though the throttle was a consistent position.

This was when I had a brick on the throttle to hold it open - for cleaning.

Maybe you need to do a throttle body reset. This can be done by removing a fuse (think fuse number 5) for a few minutes and then let the ECU relearn. Although as you have pulled negative lead from battery this should do a similar thing.

There are so many fault codes that could cause your running that it would be guessing to advise you on what your conditions might be and why they are being caused. Likewise you could be checking a whole load of things that are unnecessary when you identify the fault code.

One last thing that might help...

There have been a couple of occasions where pushing the throttle pedal has made NO difference to the revs.

That has certainly happened at rest (just after starting up).

It might also have happened on the move. Because even when it felt like the engine had died I found that it was still running as I pulled up to rest

Could be the potentiometer in the throttle pedal gone - new pedal time usually for that. Expensive new so worth getting one from a scrapper as they a) don't go wrong often and are therefore in high supply and shouldn't cost the earth.

CODES

16514: Bank 1 - Sensor 1 Electrical Problem In Circuit P0130 Intermittent

17579: Angle Sensor 2 Throttle Motor - G188 Not a Plausible Signal

17950: Angle Sensor Throttle Motor - G187 Not a Plausible Signal P1542 Intermittent

CODES

16514: Bank 1 - Sensor 1 Electrical Problem In Circuit P0130 Intermittent

17579: Angle Sensor 2 Throttle Motor - G188 Not a Plausible Signal

17950: Angle Sensor Throttle Motor - G187 Not a Plausible Signal P1542 Intermittent

Those codes all point to your throttle asm buddy as being the culprit. It appears you may need a replacement.

The fact that you metioned the position of the throttle and it loosing itself and cutting out kind of backs that theory up

I would imagine they are expensive...ouch

I am no technical guro but googled it a few times...

someone may suggest better..

good luck

Edited 22 September, 201015 yr by Bowders1

I seem to remember a post where someone said they are between £300 and £350 brand new from a dealer.

You might be able to get a second hand one for a third of that price from ebay or a breakers

Gawd...

I've booked it into an auto-electricians to check:

1.Connections from pedal to ECU

2.Connections from ECU to TB.

Looking at old posts it seems to me that loads of people have replaced the TB only to find the problem persisted. (prob eventually traced to bad wiring)

If the problem didn't disappear after spending £350 then I wouldn't be able to sleep at nights.....

I popped the angle sensor off the TB last night and had a reet good look at it. There is two angle sensing circuits based on 4 styluses being swept across an arc of ceramic. They are electrically separate by the looks of things and I'm guessing that this is because the ECU is getting two reports of angle. If they both say the same thing then its likely they are both correct.

If one sensor goes wrong then it can probably be spotted through a noisey signal. i.e really sudden differences in angle even though the ECU hasn't told the butterfly to move.

An 'implausible' signal therefore must be one out of range. ie the sensor say that the butterfly is at 120 degrees even though that isn't physically possible

The car was reporting both circuits G187 & G188 as being 'implausible' so my hope is that this was only because of a bad power supply to the circuits causing both reported angles to go west at the same time.

Anyways, the electrician will find out soon - fingers crossed...

The autoelectrician didn't find any problems, in fact he had the car for 4 days in which he ran it on different types of roads including motorways. Started it from hot, from cold and everything inbetween.

He has checked for bad connections from the pedal to the ECU and from the ECU to the TB and back again, but nothing has come to light.

Just typical of electrical faults isn't it?

It could do with either working all the time or not working at all. But no, that would be too easy......

I'm just wondering, is there a ODBC device for logging sensor readings? ie something that I could configure, just leave attached to the car, logging data on a cyclic basis?

The idea would be leave it there until the car misbehaved again then I could check out sensor traces.

I have a recurring implausible signal on angle sensor two, and I've been trying to figure out what 'implausible' means for about a year and a half now, with no luck. The two angle sensors are fed by shared power lines, and there's an individual signal line back to the ECU for each sensor. The sensors work in opposite directions, so as one is rising the other is falling. They're biased so they don't move the butterfly valve into the top/bottom 3% or so of the overall travel, which would trigger the signal high/low errors. There are also errors for shorts to high or low, so by my reckoning the only things 'implausible' can mean are

• The signal from one sensor doesn't tally with the other
• The signal from one sensor doesn' tally with the motor position, used as a reference value
• The signal from one sensor is unexpected based on a number of other values in the ECU related to the position calculation

Without knowing how the ECU makes that judgement it's impossible to know where to start tracing the fault. I've tried the following

• Swapped throttle bodies
• Carried out endless cleans and adaptions
• Resistance & continuity checked all of the relevant wires and connectors from the ECU back to the Throttle body
• Re-closed any connectors that had opened up slightly over time
• Opened up the throttle body to clean the tracks and bend the brushes back into place so they're produce even pressure.
• Patched out the wire that carries the signal from sensor two back to the ECU.

Still no joy. There's no way of predicting when the issue will happen, or working out correlating factors after it does happen. If I allow the throttle body to carry out a basic setting by turning the ignition to stage 1 and waiting for 30 seconds, it'll drive as if nothing had happened. Two starts later, all the error lights will be off again and it'll run perfectly.

The only thing I have to go on at the moment is the last time we scanned it, it reported low voltage at the position sensors, and that power supply is provided by the ECU. First time it had ever done that. I'm wondering if there's a bad connection on the board itself, or in one of the components that handles the power lines to the throttle body.

Edited 13 October, 201015 yr by Interphase

I've got a second hand TB on its way, so I will swap that in and see what happens. One thing that is ever present with the car is hesitancy during acceleration, so if the new TB sorts this then I will assume the problem has been fixed. The error codes have not re-occured since the TB angle sensor was cleaned out and the auto-electrician did his diagnosis work so difficult to tell from this alone.

I'm guessing that the hesitancy is due to the TB 'hunting' for an angle. I noticed it did this when I cleaned it out many moons ago.

If this doesn't sort it then my solution would be to use the 5v power supply from ECU to TB you mention to switch another 5v supply to the angle sensors. This could be via a relay latched up by the ignition voltage, so the supply will be electrically separate from the ECU and will be unaffected by any noise / temporary interruptions. Some circuits will have correction for supply voltage fluctuations (due to aircon / lights / heavy power usage) but since the supply to the TB is only 5V then I'm guessing that no offsets will need applying.