ECT sensor on 91 Civic.. Bad?

My wife's 91 civic is giving me error code #6 (ECT sensor)

Does this mean that the sensor is bad or that the sensor is "sensing" (?)
something bad...

My guess is it's bad.

Since I have no clue what category to look under at Majestic Honda to find
the part, and hparts.com is under construction.. and I can't find my repair
book for the car.. I was hoping someone could give me an idea of how much
the part would run me, and how easy it'd be to replace..

Thanks!

 

I think the 1991 Honda Concerto engine duplicates the 1991 Civic engine, at
least at the 1.5 liter size.

For the c.1991 Concerto,
http://www.honda.co.uk/owner/ConcertoManual/62sk301/6-100.pdf is the
troubleshooting guide for error code 6, ECT sensor (a.k.a. on this page as "TW
sensor"). This guide says it might be bad; it might not be bad, too.

From the drawing at the above site, it looks like the ECT sensor (a.k.a. "TW
sensor") is item 24 at the Majestic site, under "Engine Sub Cord-Clamp,"
http://tinyurl.com/3dzjl , $24.16 + shipping from Majestic, at least for a 91
Civic LX 1.5 liter manual, etc.

Autozone also sells one for $24 and another for $39. You can search the Autozone
site for details.

Another drawing of the location appears at
http://www.honda.co.uk/owner/ConcertoManual/62sk301/6-53.pdf , but it seems to
me to be a little misleading. Probably best to go with the first two links above
for locating the sensor.

I've never replaced one, but if I were going at this cold, I'd
- make sure the car's ignition switch was off,
- disconnect the battery ground cable
- try to disconnect the sensor electrically
- drain the coolant below the level of the sensor
- unfasten the sensor's mechanical connection

Caroline
1991 Civic LX manual 1.5 liter 153k miles

 

any way he can run an ohmmeter across the connection on the sensor
itself, and check for some kind of continuity? probably supposed to be a
different reading hot vs cold?

 

Caroline pointed you to info on it - here's some diagnostic info:
http://autotech-elearning.com/uploads/226-qis_ect.pdf

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

Don't replace anything yet.

There is a procedure for checking the sensor, but the best thing for you to
do before embarking on expensive wild-goose chases, is to clear the code
from the ECU by pulling the "Backup" or "Hazard/Backup" fuse for 10 seconds
(on right shock tower, at rear of box).

Often these problems are intermittent and the error may not repeat.

(I had a VSS sensor error once a few years ago. I cleared the code and it
never came back.)

Your "ECT" part is also called the Thermo Wax sensor, and sends a voltage
to the ECU varying with how warmed-up the engine is.

If you have an automatic transmission, do you notice delayed upshifts into
top gear? Any other odd behavior? Any corrosion on the TW sensor wires or
connector?

If the code repeats and you have a multimeter, I can send you the check
procedure from the factory manual. It's easy to check.


--
TeGGeR®

The Unofficial Honda FAQ
http://www3.telus.net/public/johnings/faq.html

How to find anything on the Internet or in Usenet Groups:
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"Tegger®" <> decided to join
the conversation on 08 Jun 2004 with message

I checked out my wife's car today.. it was really low (but not empty) on
coolant.. strange since the temperature showed normal (she says) .. i
refilled it and reset the computer.. Hopefully we don't see this light
again If we do, I'll start looking for some more options..

Thanks!

 

Watch that coolant level carefully every day for a while.

If it goes down rapidly or the reservoir fills up much higher than you
filled it originally, there are problems that need to be looked at.

If the level was that low, it would expose the TW sensor to air, which
would confuse the ECU. The coolant gauge uses a different sensor.


--
TeGGeR®

The Unofficial Honda FAQ
http://www3.telus.net/public/johnings/faq.html

How to find anything on the Internet or in Usenet Groups:
www.google.com
www.groups.google.com

 

"Tegger®" <> decided to join
the conversation on 08 Jun 2004 with message

Yeah, that makes sense.. From diagrams I've seen it is pretty high up, so
it wouldn't take much of a lack of coolant to confuse it.

If it is losing coolant, I'll have to poke around and find the bad hose. If
there is a leak, hopefully it's a hose. The radiator is only about 2 years
old.

Thanks to everyone who replied!