Audi/VW ELTH CLT sensor calibration data

[smolly]

I am using the Audi/VW OEM CLT sensor, the ELTH 078 919 501 B.
Calibration has been done with some ice and boiling water. These where the result:
Temp, degC Resistance
0 - 5940
22 - 2300
100 - 200

Now my engine temp seems a bit high and I would like to be sure that the calibration figures are correct.

Does anybody out there use this CLT sensor?
would you be so kind to share your calibration data?

thx.

[smolly]

up

[T3Bunny]

Not sure what car that sensor is off of.... As I posted in another thread the Bosch sensors are junk. Calibrating them is near impossible and if you ever change the sensor you very well may have to recalibrate it. The Bosch temp sensor tolorances litterly are that bad!

Want the simple answer? Run GM sensors. No calibration needed. I run those on all my own setups and on 90% of my installs. NEVER have problems with the GM stuff and its EASY.

[smolly]

For sure it's used in the 1.8 and 1.8T from Audi/VW. But probably also on some other VAG engines.
The big advantage is the standard place holder for the sensor and the re-use of the standard harness.
Nobody else taking use of these advantages with a similar engine?

[T3Bunny]

The people talking advantage of VW sensors do so only from a perspective of cost. As for the place holder, one of the VW block off plugs can EASILY be drilled out and tapped for the GM sensors.

Harness? Well more than 90% of my installs use all new plugs and wiring.... The cost of using old plugs simply is not a factor. Some of the VW/Audi plugs I do reuse after depinning them and cleaning (mainly because they are difficult at best to obtain), but for the most part everything is replaced. The only time I stick with stock sensors are the rare occasions where I need to retain all the stock wiring, and apperance.

I approach most of my installs from a time perspective. It takes only maybe 30-40 minutes to convert over to GM sensors. Where getting VW ones calibrated to where I am 100% happy with the numbers, has yet to happen. Having said that....

First thing I would do is get the right bias resistors into the ECU. Yes Easy Therm can compensate somewhat, but changing over to correct resistors will get you closer. I "understand" that the bias resistor should reflace the normal resistance of the sensor at "room temputure." I simply tend to go with whats been proven for the Bosch sensors. Then I use a lazer temp gun. A regular thermometer usally doesn't rise as fast as the temp changes. I use an ice bath I then heat to boiling taking multiple measurments along the way. Now in your case, all of this is already done previously and pretty much proven. So the approch to take here is simply tweaking numbers. If your MegaTune displayed temp is too high, add a little resistance to you calibration numbers up at the top and vice versa. I would definalty use a lazer temp gun though to try and dial in your readings.

And a final thought... In the end the "accuracy" of the numbers is relative. Your ECU gets tuned for what its seeing anyways. Realy the only thing bothered by inaccurate readings on the sensors is the operator.

[efahl]

I am using the Audi/VW OEM CLT sensor, the ELTH 078 919 501 B.
Calibration has been done with some ice and boiling water. These where the result:
Temp, degC Resistance
0 - 5940
22 - 2300
100 - 200

Sounds about right to me:

Date: Wed, 20 Feb 2002 16:42:22 -0500
From: "Camden Lindsay"
To: megasquirt@yahoogroups

just found this spec for an 88 audi quattro temp sensor (engine computer)

Degrees C Ohms
0 5 - 6.5K
20 2 - 3 K
50 700 - 900
100 175 - 210

hope this helps

camden