QuestionHello Roland,
Thankyou very much for your reply !
Ok, I did as asked and removed the body computer, cleaned all the contacts and used compressed canned air to clean off the board. The board did not seem wet at all. Reinstalled it and I still have all the same problems.
The instrument cluster is electronic ( just a quick note that I can see the mileage when car is first fired up, but it disappears very quicky)
The Overhead console is EVIC.
The Air Suspension is rear load leveling
All problems can be viewed on the EVIC, except the faulty odometer is on the dash, as is the low fuel gas gauge, although it does give a low fuel warning on the EVIC also.
Also, I get warning on the EVIC to calibrate the DIRECTION feature, but it won't allow me to do so.
Hope this helps you. Please let me know if there is anything else I can do to help with your diagnosis.
Jim
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Followup To
Question -
Hi Roland,
A couple weeks back, my had trouble with a loose battery clamp on the positive post. I purchase a new clamp and installed it.
Ever since then, my Fuel Gauge (shows tank as almost empty), overhead Mileage/fuel calculators, Direction of vehicle (Can't calibrate), Actual Mileage on car (odometer), Turn Signal 'on' warning beep ( This starts beeping whenever I turn on the signal , have all quit working properly. Also keep getting warnings about load level Suspension, Low Fuel and low coolant.
Can you help me trace what is causing this?
Want to offer a big thank-you for the work you do on this board... I know I very much appreciate it
Jim
Answer -
Hi Jim,
Thanks for your kind remarks.
You really have the 'state of the art' '90 vehicle! I am impressed with all the features you may have. My first inclination is to focus on the body computer and CCD bus system through which all of the problem areas seem to be related. But I don't see a tie in to changing a battery cable clamp so that is puzzling to me. Are you certain nothing else unusual happened around the time these all began? One idea is that there could have been a heavy rain or car wash experience during which some water could have leaked around the windshield and dripped down on the plugs/sockets of the body computer located on the right side kick panel just in front of the passenger side front door. So you might want to find that body computer and remove it so you can check the plugs and sockets and maybe spray some electronic circuit cleaner on the interfaces in case it is wet inside.
Then write me back and tell me more about how the vehicle is equipped (type of instrument cluster [mechanical or electronic], overhead console [called the EVIC?], air suspension system [bendix or bosch ABS]? And do the warnings appear on the EVIC?
I have the circuit diagrams and electrical systems manuals for the '90, and a body systems manual for '92 so we can probably trace out these issues. But lets try and find some experience that might have caused all these gremlins to start at once, like water intrusion of the body computer.
Roland
AnswerHi Jim,
Thanks for the kind comments.
One set of measurements you could make is at that blue CCD plug would be to check the voltages/resistances on the four wires:
The black/light green should be grounded to the body
The red should have 12V on it
The white/black and the white trace wires should each have 2.5v on them, one plus and one minus with respect to ground.
So take a look at those and watch them for a few minutes after you turn on the ignition to see if the voltages on the latter two remain constant.
The data is on the last two wires but you have to have a digital reader to detect it.
Roland
