[Fwd: Re: Temperature sensor Help please (was 5KCSTQ Cold Start]

[John Sherrow]

Ti is correct. The ECU coolant sensor is a single pin type near the
front of the engine where the upper radiator hose enters the block.
There are two identical sensors in that area. One tells the ECU the
temperature and one tells the ISV controller the temperature. You can
use a multimeter to measure the resistance from the single terminal to
the body. The temp/resistance values cited in the previous post were
correct. About 1000 ohms at room temp. R goes down as it gets hotter.

-------- Original Message --------
From: Ti Kan <ti at amb.org>
Subject: Re: Temperature sensor Help please (was 5KCSTQ Cold Start
To: petergg at dimensional.com (Peter Golledge)
CC: mulieri at physiology.med.uvm.edu (Louis A. Mulieri),
quattro at audifans.com

Peter,

The temperature sensor in question is the one for the ECU, not for the
radiator fan.  It's not a thermo "switch", but rather should have a
resistance curve that varies with temperature.

I think the sensor should only have one electrical contact on it, but
the one that Louis describes has two terminals, which leads me to
believe
that he is looking at the wrong unit.

-Ti
2003 A4 1.8T multitronic
2001 S4 biturbo 6-sp
1984 5000S turbo
1980 4000 2.0 5-sp
--
    ///  Ti Kan                Vorsprung durch Technik
   ///   AMB Laboratories, Sunnyvale, CA. USA
  ///    ti at amb.org
 //////  http://www.amb.org/ti/
///

Peter Golledge writes:
> The switch only goes closed circuit at the defined temp, which is lot
> hotter than hot water (120C? I thought).  Best plan is to heat the heat
> shield that the time switch is in with a lighter and verify that the
> fan kicks in.
>
>
> On Tue, 2003-07-22 at 07:05, Louis A. Mulieri wrote:
> > Hi Again,
> > 	After hearing from Ti Kan that type 44s have a temperature sensor
> > rather than a thermo-time switch I located and tested it. I have some
> > confusion about whether my temperature sensor is
> > defective or not on my 88 5KCSTQ. I pulled off the two harness
> > wires from the sensor and could not get anything but open
> > circuit readings on my ohm meter (2000K-ohm range). I ordered
> ...