Re: check engine light

[rawaudi@frugal.com (RWheeldon)]

Chris wrote:

>I keep getting the infamous "check" warning in my 90 (115k)...and I'm
>getting real tired of it!  Here's why:
>
>I dump the codes and I get a fault for the ECU temp sensor.  I check the
>sensor resistance and harness voltage and both seem fine.  The fault was
>intermittent so I figured that maybe the sensor was going out in spurts.

>I replaced the sensor, along w/ thermostat (which, BTW, you *can* do w/o
>removing the P/S pump), and the fault is still there.  Now it seems to only
>be present sporadically when the engine is warm (1/2 way on gauge) and
>sometimes when I'm driving (i.e., throttle open).  I cannot, however,
>replicate this every time; sometimes the lamp will light while idling and go
>away once I get moving again...
>

Broken wire or bad connector between temp sensor and ECU.  First clean all
connections and apply Stabilant 22A (Radio Shack, I think) and see if that
fixes the intermittent.  If not, start looking for a break in the wire.
Bob Wheeldon
'90 V8Q
Principal Engineer
Boeing Commercial Airplanes
robert a wheeldon@boeing.com
rawaudi@frugal.com