ACC II
Troubleshooting
ACC II will
allow the owner to run a calibration and diagnostic mode. However, it
will not display the actual codes, just the number of them present. A
little applied logic can pinpoint a course of diagnostic action
however. The calibration should be carried out whenever a problem
arises or the battery has been disconnected or discharged. Note all
the symptoms you can when a problem arises and they will help you
decide what could be the root of the problem. Distinguish if the
problem only occurs in AUTO mode, but goes away when you select the
settings manually. If the problems exist in both modes, suspect the
problem to be either in the motors running the various flaps or
mechanical in origin. If the problem exists in AUTO only, suspect a
sensor problem. Suspect the ECU only when all other diagnostics show
no problem. Run the diagnostic mode
by having the engine running and pressing AUTO and <=> (Vent)
at the same time. "0" should display in the ACC panel and will remain
there until the sequence is completed. If the previously selected
temperature returns to the display, the system has successfully
calibrated itself and found no faults. If a single digit number is
displayed, that is the number of faults in the
system.
Always check for power
and ground to the ACC unit. Never measure resistances with the ACC
control unit plugged in. Never unplug the ACC unit with the key on.
Make all measurements from the backside of the pin connectors to
prevent damage to the small pins. Make sure all connectors are clean
and fit together tightly. Look for pins that are pushed back in their
connectors. Read all procedures thoroughly and follow any warnings
they may give.