MIU Control Module Inputs, Outputs, Bus, Power, Ground

Control module inputs







- Battery voltage +30 (1)
- Battery voltage +15 (20)
- Ground connection (G33S)
- Engine oil pressure warning lamp from the oil pressure sensor (44)
- Brake fluid level warning lamp from the brake fluid level sensor (42)
- Handbrake warning lamp (43)
- Fuel level from the fuel level sensor (46)
- Low fuel level indicator lamp (46)







- Vehicle speed signal from the ABS control module (547)
- ABS warning lamp (ANTI LOCK) from the ABS control module (547)
- AIRBAG warning lamp from the airbag control module (331)
- Charging warning lamp, generator (2)
- Lights-on indicator lamp from the light switch (10)
- Main beam indicator lamp from the main beam relay (8a)

Control module inputs, bus







- Info Disp Lamp from SID (541)
- Rheostat value from SID (541)
- Rheostat Night Panel from SID (541)
- Night Panel from SID (541)
- Display lighting from SID (541)
- Light intensity in cabin from SID (541)
- Driver's door from TWICE (632)
- Passenger door from TWICE (632)
- Rear left door from TWICE (632)
- Rear right door from TWICE (632)
- Boot lid/tailgate from TWICE (632)
- Steering wheel location from TWICE (632)
- Left direction indicator from DICE (628)
- Right direction indicator from DICE (628)
- Rear fog lights from DICE (628)
- Check Engine Lamp from T7 (430b/589b)
- Shift Up Lamp from T7 (430b/589b)
- TURBO gauge from T7 (430b/589b)
- CRUISE Lamp from T7 (430b/589b)
- Fuel consumed since start from T7 (430b/589b)
- Engine speed from T7 (430b/589b)
- Coolant temperature from T7 (430b/589b)
- Wheel speed from TC/ABS (382)
- Selector lever position from TCM (502b)
- Check Gearbox lamp from TCM (502b)
- SPORT from TCM (502b)
- WINTER lamp from TCM (502b)
- ABS warning lamp from TC/ABS (382)
- TCS OFF indicator lamp from TC/ABS (382)
- TCS indicator lamp from TC/ABS (382)

Control module outputs, bus







- Vehicle speed
- Sound is used by SID (541)
- Fuel consumed since start is used by SID (541)
- Fuel level is used by SID (541), Trionic (430b/589b)
- Odometer reading is used by SID (541)
- Identification number is used by TWICE (632)
- Diagnostics communication (445)

Control module





The main instrument unit consists of three replaceable main components:
- Instrument unit
- Control module (electronic unit MIU)
- Odometer display

The control module is integrated in the main instrument unit and has two connectors; one 12-pin (K12) and one 20-pin (K20).

The control module receives information from its own sensors and switches as well as from other systems. It processes the information and uses it to control instruments and lamps. Certain information is put on the bus.

When a fault occurs, the control module stores the diagnostic trouble code. In case of replacement, a control module for that specific car must be ordered and its programming will then be carried out at Saab Automobile. The odometer reading stored in the old control module and shown on the display must be programmed into the new control module.

The instrument unit contains gauges and meters controlled by its own control module on the basis of information received from other systems as well as its own sensors. Warning and indicator lamps which are controlled by their own sensors/switches as well as control modules from other systems. All the warning lamps, indicator lamps and light bulbs (not LEDs) are replaceable.

The odometer and trip meter display is a unit with two digital counters, a six-digit counter for the odometer and a four-digit counter for the trip meter.

The control module stores the distance driven and displays it. There is a lamp in the display which is replaceable.

Diagnostics
If an internal fault occurs in the main instrument unit's control module, diagnostic trouble code B1605 is set.

Power supply

Battery Voltage (+30 circuit)









Current (+30 circuit) is supplied via fuse 35 (22a) to main instrument unit pin 7 (K12). The control module uses current from the +30 circuit for its memory.

Battery Voltage (+15 circuit)
Current (+15 circuit) is supplied via fuse 17 (22a) to main instrument unit pin 1 (K12) and pin 6 (K12).
The main instrument unit is activated by current from the +15 circuit.

Diagnostics
If there is no current supply from the +30 circuit, the trip meter will be zeroized every time the ignition is switched off.
If no +15 current is present, the main instrument unit will not be activated. The engine will not start as bus communication has not been activated.
The function has no diagnostics.

Ground









The main instrument unit is grounded through pin 2 (K12) and pin 3 (K12) to grounding point G33S. The grounding points are internally connected.

Diagnostics
If a ground connection is absent, the warning lamps, etc., that are grounded outside the main instrument unit (e.g. ABS warning lamp) will still work. Others will not.

The function has no diagnostics.