[DML] More-interesting-than-usual governor computer problem

[Peter Lucas <lucas@xxxx>]

My newly-acquired #6703 has started to show typical symptoms of early-stage
auto transmision governor computer disease: When starting out, it
occasionally starts in third, or fails to downshift to first on a stop. I
built an LED solenoid-signal monitor, and sure enough, sometimes the
third-gear solenoid signal stays high (LED off) on powerup and/or doesn't
return to high after a stop. The second-gear signal seems to behave
normally. Symptoms go away after warmup.

Ho hum, you say--another poor schmuck with a bad governor computer. Well,
maybe so, but there's more:

1) My back up lights are always on when the engine is in park, neutral, or
reverse. They go out in Drive, 1, or 2.

2) The engine will start in park, reverse, neutral, or drive, but not in 1
or 2--the start inhibit function is clearly confused.

3) On multiple (but not all) occasions, I started the car with the A/C
running, the third-gear solenoid LED came up off, and briefly powering off
the A/C made the LED come on and operate properly.

4) Downshifting to 1 or 2 has no obvious effect, even when the LEDs show
normal shifting. I.e., shifting to 2 never seems to force a downshift, and
starting in 1 does not force the trans to stay in first gear.

5) Downshifting on full-throttle functions normally.

6) The voltage across the solenoid test-points in the engine compartment
reads around 10 volts.


So, is all of this related or do I have multiple problems? I am a little
fuzzy on how many inputs the computer has. I assume it takes several inputs
from the multi-function switch. The switch is obviously screwing up
somehow. Is it possible that this is confusing the computer? Is there some
adjustment related to the switch that will get it back into synch with the
gear-shift control? Is 10 volts normal or could a power problem be causing
compter malfunction? Is this why turning off the A/C often helps? What's
with the backup lights? Should I just send in my $400?

Pete Lucas
VIN #6703

P.S. -- Is any progress being made on a reengineered computer? Seems like
it could be done pretty easily with a $6 PIC microprocessor and a few bits.
If anyone is actively working on this, I could probably help. Send me a
note.

--pete