EDU 3 Trip Computer and Clock

2��7EDU 3 Trip Computer And Clock:

WIRING DIAGRAM

EDU 3 Trip Computer And Clock: Component Location:

COMPONENT LOCATION VIEW

EDU 3 Trip Computer And Clock: Component ID:

COMPONENT ID
16 Rheostat, lighting for instruments and controls, on dashboard between the steering wheel and driver's door.
22a Fuse board behind the access panel in the glove box.
45 Engine coolant temperature sensor, on the left-hand side of the thermostat housing.
46 Fuel level sensor in fuel tank under the luggage compartment floor.

In The Main Thstrument Display Panel
47a Fuel gauge
47b Fuel level indicator lamp.
47c Coolant temperature gauge
49 Clock in the centre of the dashboard.
81 2-speed radiator fan relay, in main fuse box in front of battery.
132 Vehicle speed sensor, in the speedometer.
155 Relay, A/C radiator fan, in main fuse box in front of the battery.
159 Distribution terminal (+15 circuit), in main fuse box behind the glove box.
166 3-stage pressure switch for the radiator fan, on the receiver in front of the right-hand wheel housing.
169 A/C switch, on the dashboard between the centre panel and steering wheel.
210 EDU trip computer in the main instrument display panel.
216 ACC control module in the middle of the dashboard.
230 Distribution terminal (+30 circuit) in main fuse box behind the glove box.
242 Coolant level switch in the coolant expansion tank.
245 EDU transmission range switch (automatic transmission) beside the selector lever.
286 Outside temperature sensor, on the left-hand side behind the front spoiler.
445 (H16-1) Diagnostics test socket, below the steering wheel.
430 Saab Trionic control module in the engine bay on the left behind the bulkhead partition.
510 Motronic M2.8.1 control module, in the engine bay behind the bulkhead partition.
587 Motronic M5.2 control module, on a bracket under the dashboard.
589 Saab Trionic OBDII control module, in the engine bay on the left behind the bulkhead partition.

2-Pin Connector
H2-1 Beside the coolant expansion tank.

3-Pin Connector
H3-20 Behind the main instrument display panel beside the speedometer (ME).

4-Pin Connector
H4-4 Beside the fuel pump under the luggage compartment floor.

10-Pin Connectors
H10-15 Behind the left-hand headlamp.
H10-25 Behind the left-hand headlamp.

24-Pin Connector
H24-2 Behind the left-hand headlamp.

70-Pin Connector
H70-1 In the engine bay, behind the bulkhead partition.

Grounding Points
G8 Grounding point, dashboard, by the left-hand front loudspeaker socket.
G14 Grounding point, left-hand seat member, under the left-hand front seat.
G31 Grounding point, right-hand structural member, behind the right-hand headlamp.

DESCRIPTION OF OPERATION

EDU 3 Trip Computer And Clock: Cars With A Manual Gearbox:

Cars With A Manual Gearbox

EDU 3 Trip Computer And Clock: Cars With Automatic Transmission:

Cars With Automatic Transmission
General
The Electronic Display Unit (EDU) 3 trip computer is available in two basic versions, one for a manual gearbox and one for automatic transmission. The computer is programmable, which means that a replacement trip computer must be programmed for the car model, etc. in which it is fitted.

Programming is performed with the ISAT scan tool. In addition, the ISAT scan tool can be used to carry out certain adjustments and tests and to obtain readouts of diagnostic trouble codes.

The trip computer provides the following information:

In The Left-hand Part Of The Display
^ Current and average fuel consumption.
^ Range on remaining fuel.
^ Battery voltage.
^ Outside temperature.

In The Right-hand Part Of The Display
^ Position of selector lever (on cars with automatic transmission).
^ Current fuel consumption (horizontal scale).
^ CHECK ENGINE warning message in the event of a malfunction in the Trionic or Motronic engine management system.
^ CHECK RADIATOR LEVEL warning message if the coolant level is too low.

When the ignition is switched on, all check indicator lamps should light up and then go out one by one within 4 seconds.

Use the R and INFO buttons to select the different functions of the trip computer and the display in km or miles, for instance. The buttons are situated on clock 49 or SCC trip computer 241.

Trip computer 210 is supplied with current continuously via fuse 17 and also via fuse 13 when the ignition switch is in the Drive position.

The brightness of the display is automatically adjusted in daylight by means of a sensor on either the SCC unit or the clock. When driving in the dark, display brightness can be adjusted with rheostat 16 (lighting for instruments and controls).

Fuel Consumption
In order to calculate and display current and average fuel consumption, the trip computer requires data on:
^ the distance driven, from vehicle speed sensor 132 via pin 9.
^ actual fuel consumption, from the engine control module via pin 8. The control module uses the control pulses to the injectors, the frequency of which corresponds to the current fuel consumption.

Range On Remaining Fuel
To show the range (the distance that can be driven with the fuel remaining in the tank), fuel level sensor 46 is connected to the trip computer via pin 33. The trip computer calculates the range from the average fuel consumption over the last 20 minutes.

Quantity Of Fuel
The trip computer supplies about 12 V to the fuel gauge via pin 22. From pin 24 the trip computer supplies a 1-9 V signal which controls the reading shown on fuel gauge 47a.

1 V = tank empty
9 V = tank full

When about 10 litres of fuel remains in the tank the trip computer grounds the indicator lamp (low fuel warning 47b) via pin 25, causing the lamp to light up.

Engine Coolant Temperature
The trip computer supplies about 12 V to the coolant temperature gauge via pin 22. From pin 24 the trip computer supplies a 1-9 V signal which controls the reading shown on coolant temperature gauge 47c.

1 V = min. temp
9 V = max. temp

Outside Temperature
Information about the current outside temperature is obtained from outside temperature sensor 286 via pin 35. The sensor is located behind the car's front spoiler.

After processing, the current outside temperature value is sent to the ACC control module via pin 23. The signal is a pulse train.

The ice warning function is automatically activated and displays the outside temperature as soon as it comes within the range of -3°C to +3°C. The temperature is then shown on the display until another function is selected with the INFO button or until the outside temperature leaves the range of -6°C to +6°C, i.e. the function has a certain degree of hysteresis (delay).

Low Coolant Level
The warning signal for low coolant level is received from sensor 242 via pin 17. The sensor closes when the level is too low.

Radiator Fan Control
The radiator fans are controlled via the trip computer. By grounding relay 155 via pin 5, the fan starts at low speed (2-speed fan) or at normal speed.

Relay 81, which activates the high-speed mode on the 2-speed fan, is grounded via pin 6.

After-running of the fans is also controlled by the trip computer. When the ignition switch is turned to the OFF position, the trip computer checks the temperature of the coolant. If it is too high, the trip computer allows after-running for a maximum of 3.5 minutes.

A/C Control
When the A/C system is to be engaged, a 12 V signal is received via pin 10 from ACC control module 216 or A/C switch 169. The trip computer checks the temperature of the coolant and if it is not too high sends a 12 V signal via pin 4 to pressure switch 166 and to the engine management systems.

Check Engine
The malfunction indicator (CHECK ENGINE) lamp in the trip computer lights up if there is a fault in the Trionic or Motronic systems. The data is received via pin 12.

Gear Position Indication
On cars with automatic transmission the trip computer is connected to transmission range switch 245 via pins 18, 19 and 20.

Signals From The Clock/SCC
The following information comes from the clock or the SCC:
^ INFO button via pin 14.
^ R button via pin 15.
^ Light sensor signal via pin 36.

Backlighting
Lighting of the display is controlled by rheostat 16 and also by the value of the light sensor.

FAULT DIAGNOSIS HINTS
1. Check fuses 13 and 17.
2. Check the relevant wiring harness connections, connectors and grounding points.