No subject

Testing - Disconnect cable harness from the sensor(s)

Test using a Multimeter in the Resistance Ohm setting and an appropriate
temperature
probe (such as a thermocouple device, I've actually had good success
using a digital
meat thermometer head in firm contact to the flange/head).

at -4F (-20C) (not going to happen in the summer), resistance between the
end of the sensor and the flange ~ 6000 ohms
at 68F (20C) ~ 1000 ohms
at 176F (80C) ~ 130 ohms

If not replace.

If values okay, check for open circuits. If no opens, replace Control
Unit (I'm thinking ECU) and check
current (using multimeter in series with harness and sensor) 430 +/- 20
mA. Idle should be 750 - 850 RPM if
sensor and ECU are operating correctly.

NOT in Bentley. If the above aren't correct and no opens, check the
resistance value at the ECU to the head. The harness
wire MAY have corroded, making the ECU think the temp is cooler than
actual.

HTH,

LL - NY


From: Ti Kan <ti at amb.org>
Subject: Re: Temperature sensor Help please (was 5KCSTQ Cold Start
To: petergg at dimensional.com (Peter Golledge)
Date: Tue, 22 Jul 2003 13:25:52 -0700 (PDT)
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