Monkeyboy

aka Cam Position Sensor? (located on front of Engine)
I am getting:
17748 - Camshaft Position Sensor (G40) / Engine Speed Sensor (G28): Incor. Correlation
P1340 - 35-10 - - - Intermittent

2001 A4 1.8TQMS
No obvious issues / stutters / blips - seems to run fine.

Timing belt and etc was done Nov 2006.

I replaced the Hall Sensor @March or April 2007 trying to fix a CEL which turned out to be the cam adjuster unit.

Cam Adjuster unit replaced by independent shop (assume timing was verified at this time) @April 2007.

Based on the code (no CEL, but it shows up in VAG COM occassionally) - 1) it could be cam sensor (Hall) 2) engine speed sensor 3) incorrect timing.

- I will assume that the timing is OK based on the work done by my indy shop
- I will assume that the engine speed sensor is OK

Could I have installed the Hall sensor incorrectly when I replaced it last year? (I may have been getting this code for a long time - only got VAG COM @June 2008 when this code was present)
Appeared to be a simple part - I know I simply removed the old and installed the new (no verification of TDC if that was required??)

Hoping to eliminate the easy stuff - my hit list in order:
+ unplug / replug Hall and engine speed sensors electrical connections <b>(done)</b>
+ verify Hall sensor is installed correctly
+ replace engine speed sensor
+ replace hall sensor
+ verify timing by manually checking TDC

Any thoughts?

Monkeyboy

Doing some additional research - I found the following regarding installation of the cam position sensor:
"make sure the rotor ring is properly mounted on the camshaft. If incorrect, the locating lug will be flattened when the securing bolt is tightened"

Could be that I did not get lucky when I installed mine.

Anyone have additional details on how to properly orient the rotor ring from the cam position sensor?

thanks

cparke

The camshaft position sensor is a magnetic sensor; it doesn't have any moving parts. You can see the readings from the sensor in measuring block 90 to see if it is going out of spec. or something. That would also give you some sense of how the timing is doing.

Engine Speed Sensor (G28) is another story; I don't know much about that. This is the sensor that reports RPM's, isn't it? You can see its readings on the instrument cluster.

Monkeyboy

I just looked at a spare hall sensor I had...zero moving parts, nothing to adjust...only one way to put it on. So dead end here.

Measuring block 090 just gives me RPM (800) / Engine Load (18%) / Idle Stabilization (-15.0 KW) - nothing about timing or hall sensor phase.

Saw another reference that group 093 gives hall sensor phase info...but nothing...I posted the question in Vag-Com forum to see what block it should be.

Looked at readiness code for Camshaft Timing test (04 / 094) - and it checked out OK...I assume this means that Cam timing is OK?

Without additional info...
- replace hall sensor
- replace engine speed sensor
- tear it down and manually check timing

cparke

"Idle Stabilization" is the Camshaft Position reading (in degrees)

cparke

-15 is way out of spec.

Monkeyboy

but I'm still a bit confused -
would this point specifically to timing being off (belt jumped a tooth?)
or does this relate to cam timing via the cam chain?

what is the next best course of action?
appears that I can eliminate replaceing any sensor and jump right into checking/adjusting timing.

Do I just look at the timing belt - possibly the marks for TDC are incorrect and I'd need to manually check TDC? Inspect belt.

And/or - do I do anything with the Cam Chain - ensuring 16 rollers between marks (and I paid a shop to do this last year when my cam adjuster unit failed)

-thanks for the info

cparke

With camshaft adjustment active, timing is advanced the proper range becomes 16.0 to 25.0 ° KW (AHA doesn't have a partial camshaft adjustment function). Assuming your AWM is the same (and I imagine it would), and -15 ° KW has become the normal, that could explain the cause for the DTC.

While I suppose it could be the sensor, some timing issue could also be the problem. Somebody who knows something more about timing is going to have to help you from here, sorry.

cparke

Make sure the camshaft adjuster they installed is the right part number first, though! (some wrong part #'s will fit fine but they adjust the wrong way!)

Since camshaft adjustment is an advance of timing, should be safe for you and bring your values within the normal range. If the camshaft position sensor readings moves forward like it should, you know the sensor is good.

Monkeyboy

was 058 109 088 E which replaced 'D' but was later replaced with 'K'...have not seen cronic issues with E though...I should be OK with the part.

I just noticed that the values I gave you before Idle Stabilization = -15 KW was when reading block 093

Block 090 reads Idle Stabilization of 0 KW to -1 KW
Sorry for the confusion