The display on the on board computer no longer works, the clock is displayed but i cant go through the temp, fuel left, mpg options or these dont display

did you scan the PCM for DTC errors? first? if not why not?
this toy only works when all else works, so....
if not ,ask the dealer.
when going zero miles per hour there is no MPG.
do the math, ?
distant traveled divided by fuel consumed is.
0 div / fuel rate = 0 see? 0 /1000 is 0,

I made my own tool and it shows 200 for that and 200 for divide by zero. (when you drive and cut throttle the injectors cut fuel so fuel is zero, causing divide zero errors. ( 10 miles / 0 is ( div by zero error)
so i trap both those errors, in my software, with 200 flag , the 200 means, (can not compute MPG) see? or I could use 999.

since i didn't design the jeep PCM , i cant tell you there traps.
its just toy. but is ok cruising, use that when moving,
MPG stopped is 0.

have you tried cut fuel mode yet?
drive fast , cut throttle, hot engine, in gear, and fuel is 0 flow.
try that, and watch what it does, what you see is what you get.
my other car , with full obd2 tools, shows 190 mpg.
and is real.
see that here. buddies, top scan tool live data. and plot.
http://www.fixkick.com/my96-16v/fuel-MAF-VSS.JPG

some cars use injector pulse width (flow) to compute MPG
other use MAF air flow. and reverse compute injector rates, (tricky ask)
does this help?
my 2002 jeep has my home made MPG gauge from scratch.
(Arm processor based)

The fuse box with spare fuses, fuse removal tool and relays are located on the left wheel arch inside the engine compartment.

23 - 5 Amp Unloader Relay (K9), Rear Defogger Relay, Combination Switch, Climate Control System, Clock, Instrument Cluster, On-Board Computer

31 - 5 Amp Climate Control System, On-Board Computer, Instrument Cluster, Clock, Chime Module, On-Board Display

45 - 7.5 Amp Wiper Relay, Wiper Motor Relay, Clock, On-Board Computer, On-Board Display Check Control Module

iIn the glove box

on-board computer 23 45 (10-93 to 09-95)

on-board computer 23 45 (10-95 to 09-96)

on-board computer module, center console

Do not worry, follow these checks,

• fuses dedicated for both of them
  
• fuel sensor and temp. sensor
• their power supply
• display panel, wiring,etc
• Pls vote!!
  

hi im not a bmw expert i just have one. to set my clock you press the computer read out switch(end of indicator stick on mine) scroll through until the time of day is displayed in the panel where you see mpg,miles to next fill etc. use the small knob to the right of the display and turn it you will see the time advance stop at the right time. The display is syncronized with the clock on the dashbord. if not the right knob try the left one im doubting my memory.good luck

Hmmm. The unit that calculates the fuel is under the back seat base. There are two level sensors under covers on either side. Could be that you have a trapped wire shorting and when you go into reverse the back axle just momentarily jogs the shorted wire. I'd look at the wiring there.

clock, radio & DIC display is out. What do I need to do to fix this problem? Is it some kind of fuse?

check fuses or maybe the globe has blowen

For general awareness, the outside air temperature sensor is located above the inside mirror.
Try to reset the temperature measurement unit: 1. Switch engine on. 2. Press and hold clock minute (min) and hour (h) buttons simultaneoutly longer than 3 seconds. The display will show new temperature measurement unit. 

The sensor for the temp display in located in front of the radiator under the hood, it is round and has 2 wires going to it, plug and unplug it a few times and recheck to see if the display works, if not replace the sensor.

My expertise is more powertrain,but....probably an issue with the vehicle computer,more specifically body computer.Most vehicles now have several computers,one for the powertrain,one for the body,one for the anti lock brakes,another for the air bags,etc etc..