the mutli-MALfunction sensor strikes again!

Phil Rose pjrose at
Fri Feb 15 22:36:47 EST 2002

At 8:18 PM -0500 2/15/02, Donna or Chris Locke wrote:
>1 or 2 megohms is a low resistance?

Considering the "open" circuit that I see for a normal sensor--which
is a resistance somewhere beyond the 30 megohm range of my
meter--that couple of megs is a _relatively_  low resistance. The two
terminals in question are supposed to become grounded in case of an
engine "overheat" condition. At cooler temps they should be
completely disconnected from ground, but in the defective sensor
there is a slight conductive path to ground which is enough to fake
out the ECU.


>>  From: Phil Rose <pjrose at>
>>  Subject: Re: the mutli-MALfunction sensor strikes again!
>>  4. Disconnect once more, use DVM to measure resistance from the
>>  sensor terminals (to ground) and find suspicious low resistance (on
>>  the order of 1 or 2 megohms) from terminals R (to overheat warning)
>>  and C (to A/C). I have a spare multifunction sensor, and testing
>>  those same terminals show an open circuit with respect to ground (as
>>  expected for a good sensor).
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*  Phil & Judy Rose           Rochester, NY  *
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