How do you replace the Camshaft Position Sensor?

Hi guys, at work at the mo so can't post all the details but I think my cam position sensor has died.

I've been searching for a while yesterday and can't find any how to guides, where abouts is it located on the engine (I pressume at the top on the cambelt side?) and how easy is it to change? Thanks in advance.

Will report the detail of the problem later.

As you thought the cam position sensor is located behind the plastic cambelt top cover on the front of the engine. Its in the 4-O.clock position relative to the camshaft pulley.
No one has done a 'how to' guide
Failure of the sensor usually results in the engine taking a few more turns of the starter before it fires up - and not much else.

Cheers Spike

Thanks chap. I'll expand on my issue with my A2, it's a 2001 1.4TDI.

I've been running up and down to Edinburgh from the Midlands every weekend for the past 2.5 years, racking up ~80k miles in that time and the car has been faultless, it's only been serviced, had tyres & brakes all round.

I've suffered from the car requiring to be turned over several times (say 6 or 7) for 4-5secs at a time in order to get it start say no more than 4 or 5 times in all my ownership and after leaving the car in the airport for 2 weeks. I believe this is a drain back issue, but is seperate to my current problem.

Around 2 weeks ago I noticed the car would require cranking for a little while longer (maybe 3-4 secs) to start vs. firing straight away even when its cold outside. I understand this is the cam position sensor and it appears the only sympton of this failing.

Now, on Monday as I was getting home & about to leave the motorway the car suddenly lost power doing a constant 70mph.

As I was 1/2mile from my exit I got off and managed to make the 3 miles or so home. The car sounded & ran rough, the same way a petrol would if it's miss firing. It was idling a little erratically & when pulling off it had barely no power & ran rough up the rev range. Turbo seemed to kick in ok, but in higher gears it had no go, had to keep it in 2nd or 3rd and the revs high. Sounds like a fuel starvation issue.

I got home, turned it off and tried to turn it on but it won't fire now. It turns over at 200rpm nice and strong but won't fire up. I've misplaced my diagnostics cable so got another a couple of days back so should arrive soon. I'll report any fault codes when it does.

Now, if it's the Crank Pos'n Sensor, I would expect it would have cut out on the motorway rather than run rough? I've bought a fuel filter as I fear it may be running the original item on the car! Again, would this not degenerate over time rather than just pack up? Before letting me down the car was running tip top, very perky with Vpower diesel.

Would a faulty fuel pump (it feels like fuel starvation) be picked up by fault codes?

Thanks for your help!

Yet to read codes but from reading the forum it looks like the G28 (crankshaft pos'n) sender is dead as I understand it has no back up, but if this failed whilst running, would the engine turn itself off or would it run rough as it can't time fuelling, and then not be able to start once stopped? If that's the case it's exactly my symptoms, but can't seem to establish of people have had the engine cut out.

I believe the G40 sender (cam pos'n) is only employed for start up & if it fails the engine reverts to the G28, but the latter has no backup. Does the engine use both senders though for timing once running or only G28? I think it's the latter but cannot find this anywhere on the forum.

Finally, does the oil filter housing have to come off to get the crank sender out? Is it easy for access etc. or shall I get it done by the garage? Part is £42 from ECP.

Any thoughts?

VCDS-Lite Version: Release 1.2
Friday, 01 March 2013, 21:30:22.


Chassis Type: 8Z - Audi A2
Scan: 01,02,03,08,15,16,17,18,37,45,46,56,57,75,76,77

-------------------------------------------------------------------------------
Address 01: Engine Labels: 045-906-019-AMF.LBL
Controller: 045 906 019 G
Component: 1,4l R3 EDC 0000SG 1281
Coding: 00002
Shop #: WSC 02138
VCID: 19454E679081
WAUZZZ8ZZ1N040339 AUZ7Z0Y1738937
2 Faults Found:
17964 - Charge Pressure Control: Negative Deviation
P1556 - 35-00 - -
19464 - Shareware Version. To Decode all DTCs
P3008 - 00-00 - Please Register/Activate
Readiness: N/A

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: None
Controller: 8Z0 907 379 B
Component: ESP 20 CAN V015
Coding: 10758
Shop #: WSC 00000
VCID: 47E1D81F76B5
1 Fault Found:
01314 - Engine Control Module
79-10 - Please Check Fault Codes - Intermittent

This is the first set of codes I read before resetting them.

VCDS-Lite Version: Release 1.2
Friday, 01 March 2013, 21:34:38.


Chassis Type: 8Z - Audi A2
Scan: 01,02,03,08,15,16,17,18,37,45,46,56,57,75,76,77

-------------------------------------------------------------------------------
Address 01: Engine Labels: 045-906-019-AMF.LBL
Controller: 045 906 019 G
Component: 1,4l R3 EDC 0000SG 1281
Coding: 00002
Shop #: WSC 02138
VCID: 19454E679081
WAUZZZ8ZZ1N040339 AUZ7Z0Y1738937
1 Fault Found:
19464 - Camshaft Position Sensor (G40): Signal Out of Range
P3008 - 00-00 - -
Readiness: N/A

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: None
Controller: 8Z0 907 379 B
Component: ESP 20 CAN V015
Coding: 10758
Shop #: WSC 00000
VCID: 47E1D81F76B5
No fault code found.


Then I reset the codes, tried to start the car (cranked but didn't fire) then I read them again.

It found the errors above.

The first errors which were logged, looks like the ABS control module may have an intermittent error which is seperate to my current issue. The error code "17964 - Charge Pressure Control: Negative Deviation" appears to crop up when the engine is running with reduced power output, in limp mode or when boost pressure is too low. The car was running like this when I had the issue, then I limped home, turned the car off and wouldn't start.

After clearing the fault codes and trying to start the car again, it cropped up a G40 sender out of range which is as expected, since as I had mentioned the car had started to take longer to turn over before starting in the last 2 or 3 weeks.

So nothing else, no G28 crankshaft pos'n sender issue. Car is still not starting, might it be the fuel filter being clogged? I'll attempt to change it tomorrow. Any other ideas?