Unusual fix for Service Engine Soon Light

My '92 Saturn SL2 had the 'Service Engine Soon' light come on. Doing
the jumper on the OBD connecter gave blinks for only trouble code 26
'Quad Driver Output Fault.' Looking in the docs for code 26 showed that
the most common causes for it are

1. egr vacuum solenoid open or shorted
2. fuel vapor canister purge solenoid open or shorted
3. a/c clutch relay
4. cooling fan relay
5. burnt out dash light

I had a hard time believing that a burnt out dash light could trigger a
code 26 but I checked the dash lights and the upshift arrow light was
burned out. I replaced the dash bulb for the upshift light
and...surprise the heck out of me...it corrected the fault and no more
code 26. So...if you get the code 26 for the SES light, look at the
upshift light to be sure it's working before you start digging around
with the fuel vapor cannister purge solenoid. The upshift light does
not normally light with the key check either so you have to notice that
it doesn't turn on when you're driving. Maybe that's why it's connected
into the code 26 fault. Weird...but at least its a simple fix.

BTW, to change the bulb, you have to partially snap off the top of the
dash from the front to reach the screws that hold the front panel piece.
Unscrew the four screws along the top that anchor the front panel that
goes over the top of the instrument cluster. Then you unscrew four
screws around the instrument cluster (two on each side) which will make
the cluster loose and dangly. Then reach to the back and their is a big
mama bayonet connector on the right rear that is locked with three
little clips. A genter tug and it will pop free and the cluster will be
loose in your hand. To change the bulbs, you have to twist them out of
the back of the cluster but they are all clearly market.