Eric wrote:
> I have a 1991 Honda Accord EX with 470000 miles. Lately, I exchanged the
> thermostat and code error 6 popping up. Refer to the service manual, it is
> coolant temperature sensor. I followed the service manual and measure the
> resistance on the sensor when engine warm up with cooling fan on. It is
> open compare to spec with few hundreds ohm and I determined that it is the
> sensor problem. But when I try to measure the voltage on the sensor
> connector and I notice it is 12V instead of 5V mention on the manual. After
> that, I measured another good same year and model vehicle from my friend and
> it is 12V output on the sensor connector and the sensor is open when engine
> hot. On my friend car doesn't has the error code coming out. Would anyone
> has the similar problem and recommend which area I can check to solve this
> problem.
>
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I don't know if it will help, but did you fill the reservoir to MAX (per
the owner's manual) when you were finished with the cooling system? The
'91 can trap lots of AIR and there's no way to displace it if the
reservoir isn't full. If the coolant is low (air) the sensor will never
get immersed and so you may get error codes. Bleeding instructions are
at www.tegger.com , I expect.

'Curly'