You need to run Instrument cluster function test. To do it start engine, then press small button in the center of clock adjusting knob (not the knob itself) for more then 5 seconds. You'll need something like a sharp pencil to do it.
The first test will appear on the outside temperature display. It will read something like 35.1, were 35 is gas in the tank in liters and 1 is the number of the test. To advance to the next step pull the clock knob and turn it clockwise.
There are 9 steps:
1. Gas in the tank in liters
2. Momentary fuel consumption 34.2 is 3.4 liters per hour 2 is step number
3. Engine oil pressure in bar 20.3 means 2.0 bar step 3
4. Engine rpm x 1000
5. Engine oil level 0.5 is OK, 1.5 not OK
6. Activation of the oil pressure, fuel consumption, and fuel tank gauges - needles in the first quarteer of the dial. Indicator 0.6 for step 6
7. Activation of the oil pressure, fuel consumption, and fuel tank gauges - needles in the second quarteer of the dial. Indicator 0.7 for step 7
8. Activation of the fuel consumption, and fuel tank gauges - needles in the third quarteer of the dial. Oil pressure gauge stays in the second quarter. Indicator 0.8 for step 8
9. Activation of the fuel tank gauge, needle in the fourth quarter of the dial, oil pressure remains in the second qurter, fuel consumption remains in the third quarter. Indicator 0.9 for step 9
You need to verify oil pressure reading in step 3 and gauge in steps 6...9
Good luck, Mike