Computer Control Unit Checking and Adjusting
Computer Control Unit Connector:
Computer control unit, checking
- remove control unit
- connect voltmeter between contacts 12 and 10 of control unit connector
^ specified value: approx. 12.0 V
- connect voltmeter between contacts 12 and 11
- switch ignition ON
^ specified value: approx. 12.0 V
- connect voltmeter between contacts 12 and 15
^ specified value 9.75-10.25 V
If specified values are not attained, - check for break in wiring using current flow diagram
If specified values are attained, - check ten cable wiring harness between computer and computer control unit for continuity
- check wiring between computer and function selector switch for continuity
If computer has no display, - replace computer control unit
Computer Control Unit:
Computer control unit, adjusting
Note
When exchanging computer control units, adjust new control unit to the same code as one being replaced. If range reading (Mi) is defective, new range reading calibration must be performed.
Do the following before replacing computer control unit:
- switch ignition OFF
- press and hold reset button
- switch ignition ON
- release reset button
- read and note range reading in Mi
- switch ignition OFF
Adjust Code Switch:
After replacing control unit:
- adjust code switch (1) according to vehicle type
- switch ignition OFF
- press and hold reset button
- switch ignition ON
- release reset button
Note
Range reading (2) can be adjusted only 3/4 of a turn.
- adjust range reading with screwdriver to previously noted range
- switch ignition OFF
Computer Control Unit Code, Checking and Adjusting:
Computer control unit code, checking and adjusting
- switch ignition OFF
- press and hold reset button
- switch ignition ON
^ computer display 2000-2007
Note
When adjusting code, the computer control unit is also checked. The computer control display shows 200 when correct.
Note
The number on the extreme right specifies the selected code.
Adjust Code Switch:
- adjust code switch according to vehicle type
Code Switch
0 - Audi 5000S Turbo USA (display in miles and U.S. gallons) 6 - Audi 5000S Turbo Canada 7 - Audi 5000S Turbo Canada (display in liters and kilometers)
Range reading on computer control unit, adjusting
Note
Calibrate the range reading only after peforming the following:
^ replacing fuel gauge sensor
^ replacing computer control unit (if range reading display is defective)
Note
Calibrate range reading only with the fuel tank full.
When calibrating the range reading the computer control unit specifies an average fuel consumption of 110 liters/100 km or 23.5 MPG.
Work sequence
- switch ignition OFF
- press and hold reset button
- switch ignition ON
^ computer display 2000-2007
- check coding
Note
The number on the extreme right specifies the code of the computer control unit.
- release reset button
^ specified value: in km approx. 800 in mi approx. 500
Calibration Screw:
Note
Range reading calibration (2) can be adjusted by turning only 3/4 turn between stops.
- turn calibration screw (2) with screw driver
^ specified value: in km approx. 750 in mi approx. 465
If specified value cannot be attained, - check fuel gauge
- repeat range reading calibration
If specified value still cannot be attained, - replace computer control unit.
FUEL CONSUMPTION DISPLAY (0 MPG), CORRECTING 5000S TURBO USA:
Fuel consumption display (MPG), correcting 5000S Turbo USA
Note
If actual fuel consumption deviates more than 10% from fuel consumption calculated by computer, a correction of +/- 15% can be made.
Correct fuel consumption reading by installing permanent jumper wire from a power source to terminals 20 and/or 21 on computer control unit connector.
Correction range
^ contact 21 +/- 5%
^ contact 20 +/- 10%
Work sequence
- remove computer control unit
- connect jumper wires to connector according to chart