16706 - Engine Speed Sensor (G28)
 

Hello all!

I`ve got a 2004 A8 4,2 petrol (BFM)

Wife called the other day. "It wont start"! :Confused:

I hooked up the VAG-COM and among the usual complaints as engine mount and system too lean messages I had a new one:

16706 - Engine Speed Sensor (G28)
P0322 - 004 - No Signal - Intermittent

The car starts eventually - so far it has not died when driven.

I could not find any info about this sensor or related issues on the forum, so atleast I took a couple of pictures in the process.

So far I haven`t identified the fault. There is no procedure for checking, not even a location in the workshopmanual - dissapointing really!

I checked the resistance of the sensor. it was arount 1K. (Was just under when checking from pin #2 to #3 and just above when reversing - cannot understand why...)
The sensor acts as expected. The resistance value changes, and resumes original value when a metal object is placed on the sensor tip. The same thing happens when the metal object is removed...

Question:

Has anyone experienced the same issue?

Very common fault across all models. Just replace it.

is this the engine crankshaft sensor?

My thread I created the other day sounds similar - I've bought just the camshaft positioning sensors.. wonder if I should have bought this sensor too:Confused:

Hello "IT D3"

I saw youre thread, and yes the symptoms sounds alike. Did you get a read out?

Engine refusing to start can be caused bu quite a fiew reasons. One "field trick" I`m not a 100% sure of, but fairly confedent is that if the rev counter comes alive while you are cranking, the G28 is alive since it`s the source of the rpm signal both for ECU and rev counter.

I had lend my VAG-COM to a friend so I could not perform the scan right away.
I had a fuel pump I had plans to replace anyway. (Fault isolation for that system to lean fault). and of course if the fuel pump is dead...= no joy though. :hammer:The 8 still refused to start some times.

So I "had to do some corona comprimising and get the VAG-COM. That is what lead me on track to the G28 sensor.

I have not yet decided wether or not I`ll replace the sensor, or try further investigation.

I remember having tested a sensor of "similar" type on my old Audi V8 (D11) I`ll see if I can find that test (Involves an LED and a resistor and some stuff). The point is that it flashes if there is a signal. So if it flashes, and the ECU still doesn`t detect a signal - then it`s the ECU that`s faulty. (Yes I have a way of complicating things....)

I`ll give the "stealer" a call monday.

In the mean time I`ll struggle with the head cover gaskets..:angry2: words are not enough!

Hi Pellesin, thanks for the reply well I changed the camshaft sensor but had no joy which leads me to suspect the Crankshaft Sensor is faulty.

Does anyone know whether Lucas SEB 1400 Crank sensor is the correct fitment for a Audi A8 2006 3.7 V8 Petrol?

I'm getting mixed matches from eBay some seller say it's a direct replacement others say it isn't.

Very confusing - if anyone can confirm that would be great +++

Pellesin, don't mean to hijack your thread but it looks like we have the same issue I suspect.

Right, I have been getting all sorts of conflicting information about the Lucas crank sensors.

To be on the safe side I've ordered a Bosch one with part number 0261 210 245 which I hope does the trick.

Is replacement an easy DIY job? My friend and I hope to attempt it this week.

The camshaft sensor's were very straight forward to replace and took about 45 mins tops+++

Is it easy to replace?
 

Not in my opinion!
Everything is in the way. And all screws are hard to access.
I took a picture to show the location.
Allso, I bought a sensor from the "stealer" and lo and behold it was actually cheaper than the after market ones.

Ah great, so it another tricky job then!

How long did it take you? Also how much was the sensor if you don't mind me asking?

Thanks

Price is approx 155 euro

I`m not finished with replacement yet. I ordered the part today - but I estemate that if you have a whole work day and some zip-ties you should get it and time for tea as well:)

It`s one of those jobs that if you are not a bit "seasoned" when it comes to wrenching, you`ll give up!

Here`s a link to a bloke that made a video:

https://www.youtube.com/watch?v=ds6Mr9e_lnU


He "gives it all the names" but its the right sensor. And it can be reached with the car on jack stands - if you don`t have a lift - I don`t. Just like the picture I have attached in the initial message the heatcover for the driveshaft is removevd. It has to come off since the sensor wire is behind the cover inboard of the heatcover. You`ll understand as soon as you have a look.

That is the best answer I can give I guess. But take youre time, have some different tools to fiddle around with - and you`ll get it+++

Pellesin

Thanks for the useful information+++

Well I ordered a Bosch one for £119 but the seller cancelled the order.

I will also try the stealers as well.