The Audi Quattro
Ongoing Restoration
Info / Data

Digital Dash Information and Diagnostics,
Audi Quattro and Coupe GT

The famous Digital Dash first appeared in the Audi Quattro, in the 84 model year cars. This was the Green dash, with Vacuum Flurescent displays. This also seems to have been an option on the LHD Coupe quattro and Coupe GT, but there are rumours that several RHD examples got the dash as well.... It's also shown in the handbook for the RHD cars, with a full english translation for it's operation, etc. The Orange / Red dash was fitted to the MB and RR Quattro, and also to the North American Coupe GT.

Dash Documentation
Dash Diagnostics
Photos of the components of the Digital Dash system
Digital Dash powered up
Red / Orange Digital Dash Wiring pinout
Wiring Diagram for the Coupe / Coupe Quattro with the green digital Dash installed

Removal of the Analogue Instrument unit and replacement with an Orange Digital Dash, 1985 KV engined Coupe Quattro

Dash Documentation

Audi published a booklet "Electronic Instrument Display for the Audi Coupe GT". This details the pin-out of the 35 pin connector at the rear of the dash, and what each pin is connected to, and what each pin does. You can find a zipped copy of the booklet here : 


I've also listed links to the individual pages as well.

Front Cover
Table of Contents

Page : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

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Dash Diagnostics

Thanks to Derek from quattroforum for supplying this article on Digital Dash Diagnostics. Includes a circuit diagram for the digital dash system

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Photos of the components of the Digital Dash system

Digital Dash Unit

On the first photo, you can see the wiring tail (from the donor car), and also the three halogen bulbs. To remove and replace the 3 halogen bulbs, you need a pair of long nosed pliers.

Gearbox Speed sensor

The speed sensor is the black cylindrical item. The aluminium item is the threaded boss from the gearbox, and the ivory coloured item the speedometer cable drive gear. The speed sensor just screws onto gearbox where the speedometer cable normally goes. The three pin connector is from the donor car wiring harness.

Fuel Metering plate

On the side of the metering plate is a potentiometer. This measures the angle of the "flap" that meters the amount of fuel being delivered to the engine. The dash uses this information for calculation of MPG, etc. You can see the potentiometer on the side of the metering plate. (photos from KV engine component)

Light sensor

This tucks into the triangular vent in the side of the dash top cover. The dash uses this sensor, and another light sensor on the face of the main dash to set the brightness level of the dash.

Light sensor fitted to left hand side of the binnacle. It is a much tighter fit than the ordinary vent moulding

Dash backlight adjuster

Used to adjust the light setting of the dash, plus it works in conjunction with the computer switch.

Computer Switch

Used to control the dash, change from kph to mph, etc. etc.

Computer switch, and the digiDash / non-DigiDash dimmer switches. The DigiDash dimmer switch has the white chevron printed on it

Multi-plug connector

This connects the dash to the rest of the car

Dash surround

All switches shown clipped into place

Dash Internals

(slightly fuzzy)Photos of the (orange) dash with the covers removed

At the top right hand corner of the next photo, you can see 4 gold contacts on the glass of the LCD module. The grey 4 way conductors with the black connectors fit on here. THIS IS VERY FRAGILE! You will probably only get 4 attempts at making/breaking this connection before it fails.

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Digital Dash powered up

Red / Orange DigiDash at initial power up. This must be the dash self test, where all segments of the LCD panels are switched on to show that they are all functional....

After a couple of seconds, it returns to a more conventional appearance

Dash display minimised by pushing on the dimmer switch button.

Red / Orange DigiDash warning lights (USA Coupe GT version)

A little known perculiarity of the red DigiDash is that it stops counting on it's odomoter at 310,512 miles, or 500,000Km.....

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Red / Orange Digital Dash Wiring pinout 
(USA Coupe GT version)

Pin number Wire Colour Connected to / Notes
1 N/C (not connected)  
2 White / Red Dimmer Switch Pin 2
3 N/C
4 Green / Violet Electronic Ignition system Control Unit 
Connected to Pin 7 
5 Red / Yellow Speed Sensor Pin 2
6 Blue / Green Computer Switch Pin 1 
7 Green / Blue Computer Switch Pin 4 
8 Gray / Red Dash Light Sensor Pin 2
9 Green / Violet Computer Switch Pin 5 
10 Yellow / Black Pin 1 on Airflow Sensor (white / yellow)
11 White / Yellow Fuse S16 (30A) on Busbar X 
Connected to circuit at the demister switch
12 White / Yellow Dimmer Switch Pins 1 and 6
13 White Light Switch
14 Blue  Alternator Warning light
15 2 x Black / Blue Rear Windows De-mister Switch
16 Gray / Yellow Handbrake warning Light. 
17 N/C
18 Black / Green Right hand indicator.
Connected to corresponding colour conductor on the Hazard warning switch
19 Red / Blue This Pins linked together. Fuse S4 (15A) Busbar 30. 
21 Brown These pins linked together. Ground
Connected to the chassis
23 Black / Red Seat belt warning. 
24 Violet / Black Fuel Guage sender.
25 White / Green Dimmer Switch Pin 4
26 Blue / Brown Coolant Temp Sender
27 Blue / Yellow Low Coolant
28 White / Violet Pin 3 on Airflow sensor
29 Green Pin 2 on Airflow sensor
30 Yellow Dash Light Sensor Pin 1
31 Blue / White Headlight Hi-Beam
32 Gray / Brown Seat Belt Warning.
33 N/C
34 Black / White Left hand indicators
Connected to corresponding colour conductor on the Hazard warning switch
35 White Rear Window Demister.

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Wiring Diagram for the Coupe / Coupe Quattro with the green digital Dash installed

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Corrections, Ommissions, Errata, etc.

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