The Check Engine light has been on for a while on my 89 300TE. I have
to smog it this month to renew the California tabs, so I have to get
the light to turn off and fix whatever caused it.
It has the 8 connector self-diagnostic unit with a push button and
LED, some instructions I pulled out of On Demand made it look like it
would be easy to get the failure codes but no luck so far.
I push the buttton and hold it for various amounts of time, but the
LED never flashes. I've tried it with Ignition off, Ignittion on
engine stopped, and with engine running - nothing!
I put an old analog multimeter between pins 1 and 3 with the ignition
on, there is constant voltage, no fluctuation that would indicate
impulses. The voltage turns off when the button is depressed.
Anybody familiar with these Self-Diagnostics? Hopefully I'm
overlooking something obvious.