Coolant temp sender

[voteforpedro]

Where's it located on an AEB?

 

[Broken Byzan]

Back of the head in the stupid plastic housing/ Will more than likely have a blue plug on it. Its secured in with a clip

 

[voteforpedro]

Back of the head in the stupid plastic housing/ Will more than likely have a blue plug on it. Its secured in with a clip

Cheers mate.

 

[voteforpedro]

So I changed the CTS today (and oil change, resulting in spilling 5 litres of oil all over my garage floor...).

Still no change.

I did the climate control trick (up + recycle, 49c, recycle) and it still reads 0 degrees, even after a sprint around the block. I got a bit confused about the o-ring. I didn't see the old one because the pressure sent it flying across my garage as I removed it. I first put it up against the rim of actual sensor, but when I put the clip on it was really loose and would have leaked coolant everywhere. So I pushed it over the top of the sender (the pins) and positioned it in the gap where the clip slides in. It fits a treat with the clip but it's still reading 0 degrees.

I'm lost. Help me God.

 

[Geeman]

That's really strange.

I'd be interested to know what the problem is and how to cure it!

Sure you've not got an air-lock somewhere?

 

[andybnwc]

Not sure whats been tried or what the full problem is but what about the tstat?

 

[voteforpedro]

If the climate control trick does actually show the temp the ECU is reading, then I doubt it's the t-stat or an airlock. In both cases, surely the water temp would rise above 0 degrees. Even with a faulty thermostat, the coolant temp would be either low (but definitely greater than zero) or stupidly high (it's getting got in here, so take off all your clothes).

Methinks the electric gremlins have returned.

 

[andybnwc]

ah miss read that bit , no should go up a little bit even with bad thermostat. theres more sensors the same looking on the s4 dunno about yours tho

 

[aragorn]

Forget the climate. Get vagcom on it and look in the measuring blocks.

Could be faulty wiring, ie a broken cable.

 

[voteforpedro]

Group 001: Coolant temperature 0-3 ms
Group 004: Coolant temperature 0.0 g/s

Just noticed that it's spitting coolant everywhere at the sensor so I must have fitted it incorrectly. Although the connector is touching the water so I would expect to still get a reading. :s

Fault codes:

8 Faults Found:

17978 - Engine Start Blocked by Immobilizer

P1570 - 35-10 - - - Intermittent

16885 - Shareware Version. To Decode all DTCs

P0501 - 35-10 - Please Register/Activate - Intermittent VEHICLE SPEED SENSOR???

00532 - Shareware Version. To Decode all DTCs

07-10 - Please Register/Activate - Intermittent SUPPLY VOLTAGE B+: SIGNAL TOO LOW???

17733 - Knock-Control: Cylinder 1: Regulation Limit Exceeded

P1325 - 35-10 - - - Intermittent

17734 - Shareware Version. To Decode all DTCs

P1326 - 35-10 - Please Register/Activate - Intermittent O2 SENSOR???

16500 - Shareware Version. To Decode all DTCs

P0116 - 35-10 - Please Register/Activate - Intermittent THERMOSTAT???

00670 - Throttle Position Sensor (G127)

27-10 - Implausible Signal - Intermittent

00515 - Shareware Version. To Decode all DTCs

30-00 - Please Register/Activate CAMSHAFT POSITION SENSOR???

 

[aragorn]

Yikes quite a lot going on there.

Are they all fresh? IE if you clear them, do they all come back?

I suspect its something similar to the problem on here the other day after the boy had fitted a stereo. Turned out the wiring to one of the sensors had chafed thru, grounding out that "branch" of the wiring loom.

Also, Free Vagcom is a bit strange with 1.8T's, Those figures you've quoted arent coolant temp readings. flick thru the ones around there and look for degrees C in the units. IIRC the one you want will display two, the coolant temp on panel 3 and intake temp on panel 4, but they're mislabelled.

 

[voteforpedro]

Whoever said the "climate control code" for the CTS reading was 49 was incorrect! See here:

http://www.wak-tt.com/tt/climatecontcodes.htm

I tapped 51 in from cold start before my commute home and it read 17. The first digit was BIG and the small digit was SMALL. I thought this meant 1.7 (see photo) but when it eventually got to 60 I could see the temperature dial had moved slightly. It got as high as 66 degrees over my 40 minute drive and I could see this on the dial.

So... if that was indeed the engine coolant temperature, I guess I need a new thermostat, as suggested in the fault codes above.

I could see the thermostat housing during my escapade underneath the car... Looks an easy replacement, albeit upside down lol.

 

[aragorn]

yep, one point though, the rubber o ring goes underneath the sensor, not above it....

If you look at that image, the brass section has three steps, thin, medium and large. the oring sits on the medium bit.

 

[voteforpedro]

Yes, I sorted that in the end. I just had to give it a gentle push down when I slide the clip back into place. Now it's in securely and not spitting water everywhere.

 

[AndyMac]

IIRC code 51 is oil temp isn't it? Regardless 49 on my B5 displays 87-93 always when engine is up to temp so they've got it wrong on that site one way or the other

 

[aragorn]

what does 51 display on yours andy?

 

[voteforpedro]

Is yours a facelift?

 

[voteforpedro]

Another website indicating the same...

http://www.audi4ever.at/faq/pdf/klimacodes.pdf

 

[voteforpedro]

Also my oil temp is low. It's slightly higher than the water temp (i.e. I get a low reading on oil temp dial when water temp is circa 55 degrees). I read oil temp is always slightly higher than water temp, so if I have a dodgy t-stat, should I get a low oil temp too?

 

[aragorn]

The oil is cooled by a heat exchanger mounted above the oil filter, so if your coolants running low, it will cool the oil too.