timtt

Hi,

I'm running a 996 GT3 engine with an aftermarket ECU (AEM Infinity) and need to know the calibration values of the stock VDO coolant temperature sensor. It's Porsche part # 996 606 410 00 and VDO part # 805/41/5. VDO won't disclose it to me since it's Porsche proprietary. Does anyone happen to have the temp vs. resistance values for this sensor?

Thanks,

Tim

ninerguru

Found this test procedure for the Instrument Cluster... Looks like 20C = 1K ohms...

Test point 10
Coolant temperature
Engine off {with engine cold}
PST2 display:
Tester display corresponds to the ambient temperature.
Engine runs at idle speed at operating temperature
PST2 display:
Tester display corresponds to the coolant temperature of
80 C...lOO° C.
Troubleshooting:
Resistancvea lues:
Switch off ignition
Disconnect plug connection X3/1
Ohmmeter on pin 29 and pin 30 on the sleeve side
Ohmmeter display at 20 C: approx. 1 K ohm
Switch ignition on
Measure voltage at plug connection X3/1 pin 29 and pin 30 on pin
side
Voltmeter display: approx. 5 V
Switch off ignition
.

timtt

I found the answer, in somewhat annoying fashion. Turns out it's the same as a Bosch NTC M12 sensor which is preconfigured in the AEM and I'd preselected that on a whim in the software. The resting ambient temperature was ok, but that didn't mean it would be correct at operating temperature, so went on this wild goose chase to figure out the VDO values.

I put the VDO in a water bath and measured resistance as temperature went up. The measurements were pretty spot on, as close as I could get with my somewhat primitive measuring tools.

Here's the Bosch spec sheet for anyone that might need it: http://www.bosch-motorsport.de/en-US...2782569739.pdf

timtt

@ninerguru: thanks anyway for your help though! Forgot to acknowledge :-)