Intermittant speedo and chk engine lite on 91 accord

Hi all,

I have a 1991 Accord 5 speed.

Recently I noticed that the speedometer quit working. Then after a
longer drive it started working, then quit working etc. Also about
this same time I got a Check Engine lite. I checked and found that I
did indeed have an engine. Seriously, I checked the oil etc for any
obvious problems. The lite also went away, although not necessarily
at the same time the speedometer started working.

Any hints?

Thanks,
Steve

 

A guess - the Vehicle Speed Sensor (VSS) is failing. The engine management
system likely cares how fast you are going, thus the Check Engine light. It
could be worse. My wife had a friend whose late model Buick's VSS failed
entirely while waiting at a light; the CEL came on. When she took off the
electronically controlled transmission wouldn't shift out of first gear -
after all, what gear should it be in if the car is not moving?

In your 91, the codes are probably gone after the light goes out. If it
comes back, retrieve the codes (http://tinyurl.com/y6scej) and record them.
You will need a small shorting jumper - a short piece of small guage wire
works well - to substitute for the "Code Reader" the manual describes. As
mentioned on sheet 18 of the pdf, the connector you need to access is under
the dashboard on the passenger side.

Your approach to the "check engine" light is approximately right. The light
is there to notify the driver of emission-related problems that often don't
show up as operational problems; there are no critical warnings (like engine
temperature or oil pressure) involved. It is really saying, "I have
information for you." Rarely, the failure may cause the mixture to run very
rich and prolonged hard driving could damage the catalytic converter.
Because of that I recommend avoiding the freeway, or at least following
behind heavy trucks if freeways are unavoidable, until you can determine
whether fuel economy is near normal. Once that has been determined
restrictions are off, but the light should be investigated when practical.
If the light is accompanied by lots of misfiring or things like that, of
course you have to respond to the other symptoms.

Mike

 

Thanks Mike, and for the pointer to Code Reader. Hmmm, by the way
how did she get the Buick to stop?!

So it sounds like it's related to the speedo not working as well. It
looks like a mechanical odo, how does that work? Is the speedo/odo
all driven by electronics?

I'll try to catch the code and let you know. So far I appear to be
getting my usual good mileage and no obvious problems.

Steve

 

Yes - I'm pretty sure the speedo/odo in the '91 is all electronic. Honda's
been doing it that way for quite a while.

Mi9ke

 

I've just suffered a similar problem with my 91 prelude SI states model
with a B21a motor. I'm getting an error code 17 on one computer and 4 on
the other(can't remember which one is which). Honda quoted NZ$295 and
two weeks and $10 shipping from Japan for the Vehicle Speed Sensor
located on the transmission.
I found the following link very helpful in diagnosing the fault.
http://www.honda.co.uk/car/owner/workshop.html

 

species5618 wrote:

Thanks! I'm checking it out . . .

 

Here is a link to figure out your fault code
http://www.troublecodes.net/honda/