dont know what to do any help would be great!

[stoneA3]

hi all i am new to this forum been guided here from Audizine

we bought a y/2001 audi a3 1.8t (150bhp) just over a week ago now, we bought the car knowing the engine management light was on as the seller had a diagnostics done and it come up with cam shaft sensor.

we changed the cam shaft sensor engine management light stayed on, car will not start first time takes 2-7 attempts and when you can drive the car its very juddery and in limp mode.

we called the AA out and they said change the crank shaft sensor, we did this and still no joy the juddering gets worse and cant go over 1500 rpm, we changed the spark plugs still no joy, had the AA out again and they said there was random misfires and again the cam shaft sensor (which has been changed) so his conclusion was the ECU is faulty, we found a recondition ECU which also the company put a stage 1 remap on it for us (we were going to do this anyway) we changed that today and still no joy.

so again the AA were called and he said there was a random misfire so we changed the coil packs (all 4)
the light has gone off now and is driving a little bit better with less juddering but still it will not start first time.

the only thing the AA can now come up with is its a wiring loom problem.

does anyone have any idea what could be wrong any help or advice would be really appreciated

many thanks
louise

 

[Ste_Nova]

Vcds scan needed

 

[<tuffty/>]

As above... whats the exact fault code/message as it could be something completely different... there are a few codes related to the cam pos sensor... has it had a recent cam belt?

<tuffty/>

 

[NHN]

I had the same error come up after a belt change which is why I wonder as tuffty mentioned.

 

[<tuffty/>]

If the belt has been put on incorrectly (a tooth or more out) you will get an incorrect correlation fault code like this
17748/P1340/004928 - Ross-Tech Wiki


17748/P1340/004928 - Camshaft Position Sensor (G40) / Engine Speed Sensor (G28): Incor. Correlation
Possible Causes

Timing Belt/Chain incorrectly installed
Timing Chain probably lengthened
Camshaft Position Sensor (G40) faulty
Engine Speed Sensor (G28) faulty

Possible Solutions

Check Timing Belt/Chain installation
Use Measuring Value Blocks (MVB) to Check Timing Chain
Check/Replace Camshaft Position Sensor (G40)
Check/Replace Engine Speed Sensor (G28)

<tuffty/>

 

[stoneA3]

yes it had a cam belt changed at 110k its on 115 now, what is vcds scan please

cheers
louise

 

[stoneA3]

thank you very much for that information that could be a great help i will let my other half know when he gets home as its getting very annoying and expensive now lol he was going to strip the wiring loom on sunday and check for any breakages etc but will get him to check all them things first.

i dont suppose we done too bad the car cost £850 it done 115k with full services history and recent cam belt etc in the silvery blue colour. and weve bought a new ecu with remap at £230 coil packs £96 cam shaft sensor and crankshaft sensor and spark plugs were £130 but thats so far we dont really want to chuck any more money at it.

thanks all for the advice really appreciate it
cheers
louise

If the belt has been put on incorrectly (a tooth or more out) you will get an incorrect correlation fault code like this
17748/P1340/004928 - Ross-Tech Wiki


17748/P1340/004928 - Camshaft Position Sensor (G40) / Engine Speed Sensor (G28): Incor. Correlation
Possible Causes

Timing Belt/Chain incorrectly installed
Timing Chain probably lengthened
Camshaft Position Sensor (G40) faulty
Engine Speed Sensor (G28) faulty

Possible Solutions

Check Timing Belt/Chain installation
Use Measuring Value Blocks (MVB) to Check Timing Chain
Check/Replace Camshaft Position Sensor (G40)
Check/Replace Engine Speed Sensor (G28)

<tuffty/>

 

[<tuffty/>]

VCDS is diagnostic software used primarily for VAG cars (Audi, Seat, VW, Skoda).. a scan is used to view fault codes in the cars various electronic modules and if present will give clues to whats going on (and I mean clues as its never as clear cut as it has a fault code therefore its faulty..)

Generic code scanners aren't as good as VCDS is for VAG based cars tbh... if you don't have it yourself then have a look on the VCDS forum here on Audi Sport and haev a look on the map thread to see if any one near you would be willing to help

It sounds plausible that its the belt that the issue seeing as it was only done 5k again and the CEL (check engine light) has been on for a while

A scan will help along with the fault code(s) it might bring up

<tuffty/>

 

[marty.h]

did you use geniune or patern parts as i have in the past had a lot of problems with pattern crank , cam sensors genuine all the time on them for me now.

A week ago my mate's leon was not running right vag com said Crankshaft sensor so he got one a pattern one and i expressed to get genuine and loan behold problem was still there so he opted to take it to a garage instead of me looking at it again for them to diagnose crank sensor they fitted a genuine crank sensor and that sorted it. Needless to say i wont bother looking at his car for him again not like i ever charge him

 

[stoneA3]

we got bosch parts i rang audi and he said only use bosch parts as thats what they use :s we had the original sensors checked and there is nothing wrong with them thats why they said ecu or wiring prob grrrr its jus our luck we have nothing but bad luck lol our volvo t4 bottom end went 2 weeks ago so bought the audi and now this lol.
thanks
louise

did you use geniune or patern parts as i have in the past had a lot of problems with pattern crank , cam sensors genuine all the time on them for me now.

A week ago my mate's leon was not running right vag com said Crankshaft sensor so he got one a pattern one and i expressed to get genuine and loan behold problem was still there so he opted to take it to a garage instead of me looking at it again for them to diagnose crank sensor they fitted a genuine crank sensor and that sorted it. Needless to say i wont bother looking at his car for him again not like i ever charge him

 

[<tuffty/>]

Should add... the AA bloke seems a little out of his depth... WTF is he doing recommending an ECU swap? they can be damaged by water but thats fairly terminal and the car won't start... same for the crank sensor... if thats dead the car won't start...

Get the car scanned using VCDS and post up the fault codes...

<tuffty/>

 

[stoneA3]

just looked through maps and typically our luck again the one that was in south wales has moved lol we will try to find someone that got one and i will post the codes up as soon as we get them hopefully this weekend.

thanks again
louise

Should add... the AA bloke seems a little out of his depth... WTF is he doing recommending an ECU swap? they can be damaged by water but thats fairly terminal and the car won't start... same for the crank sensor... if thats dead the car won't start...

Get the car scanned using VCDS and post up the fault codes...

<tuffty/>

 

[marty.h]

Should add... the AA bloke seems a little out of his depth... WTF is he doing recommending an ECU swap? they can be damaged by water but thats fairly terminal and the car won't start... same for the crank sensor... if thats dead the car won't start...

Get the car scanned using VCDS and post up the fault codes...

<tuffty/>

I agree with the water thing and with all the water we have had i would have a good look around for water ingress. And where you loacated someone local to you may be able to pop and take a look

 

[stoneA3]

just messaged ljames who is from the bridgend area to see if he can help etc thanks again all
louise

 

[Broken Byzan]

Cam timing incorrect would be my guess, I bet it's had a replacement chain tensioner at some point.

 

[Geoff-R]

just messaged ljames who is from the bridgend area to see if he can help etc thanks again all
louise

I would scan it for you, I'm in Cardiff but I'm not around until Sunday evening at the earliest.

 

[stoneA3]

hi sorry late reply been out all day kids had a party to go to, my partner been out today with his brother and his brothers mate had one of them code readers and done it for us, and it was the cam shaft sensor again coming up but he done a test on the wiring loom and on one of the pins was reading 12 ohms when ment to be 0ohms so again come to conclusion its the wiring loom. :s
many thanks for all your help he is going to strip the wiring loom tommorow and have a good look through for broken wires etc.
thanks again
louise

I would scan it for you, I'm in Cardiff but I'm not around until Sunday evening at the earliest.

 

[jezzy]

Hi and welcome
I bought this and the software is free (vcds lite) VAG COM USB ODB2 DIAGNOSTIC CABLE 409.1 OBD2 II LEAD | eBay
It has worked great and will tell you the fault codes your car is suffering from.
i had a T4 and loved it, a real wolf in sheeps clothing.

 

[stoneA3]

grr this car is now doing my other halfs sweed in hes taken wires off etcc cant find a break in any wire all earths look ok that he could find etc also forgot to mention that the side light bulb blew and fuse so changed for new and keeps blowing the fuse and dash lights wont work this car is close to taking a swim lol also hes asking how can he check the timing to see if its corect many thanks to all thats helpd so far we really do apriciate it all the garages want in exess of £60+ per hour
p.s took the old ecu apart no signs of any water damage and the engine lights back on grrr

 

[marty.h]

Ideally you want someone who knows there way around a car mechanically and electronically.

A very easy test to see if it could be an earthing problem is get a jump lead from the earth on your batter and clip it onto the engine.

As for the wiring there is no need to strip the loom back just check continuity from the plug to ECU on the correct pin

As you are having a problem with camshaft sensor here is some useful info

Pic of ECU plug is looking at it with pins facing you

As for checking the timing here are the diagrams

Cambelt timing marks

Timing chain marks

hope that helps

 

[stoneA3]

many thanks for that im guna pop over my old mans tmz and steal his multimeter and see what happens thanks again

 

[minimatto]

you have PM