SAAB WIS ONLINE

Bus communication

Bus communication



Trionic, engine management system (TRIONIC)

TCM (Transmission Control Module), control module for automatic transmission (502)

TC/ABS, (Traction Control) (382)

P-bus (Powertrain bus)

MIU (Main Instrument Unit) (540)

I-bus (Instrument bus)

SID (Saab Information Display) (541)

TWICE (Theft Warning Integrated Central Electronics) (632)

ACC (Automatic Climate Control) (216)

Audio system, main unit (353)

CDC (CD changer) (355)

PSM (Power Seat Memory) (357Dk)

PMM (Power Mirror Memory) (611)

DICE (Dashboard Integrated Central Electronics) (628)

Data link connector (H16-5/445)

Airbag (SRS) (331)

ABS (Anti-lock Brake System) (547)

SPA (Saab Parking Assistance) (630)


P-Bus and I-Bus


A bus is understood to be the leads over which information is sent digitally and serially. Digital means that the voltage difference between the leads has only two values, roughly 0 V and 5 V. The information is coded so that different combinations of 0 V and 5 V pulses have different meanings.

Serial means that the information is sent in ”packets” which are transmitted one after the other in rapid succession.

All control modules in the Saab 9-5 are connected to a bus with the exception of ABS and SRS. For cars with Traction Control, the TC/ABS control module is connected to the P-bus.

The bus consists of a P-bus (Powertrain Bus) and an I-bus (Instrument Bus). Both buses are connected to the MIU (Main Instrument Unit). The buses are electrically isolated from each other.

The diagnostic tool is not connected directly to the bus but communicates via the DICE, one of the control modules connected to the I-bus, and so has access to all control modules connected to the bus.

The data transfer rate of the P-bus is ten times faster than that of the I-bus. The reason for this is that the powertrain systems need information with the least possible delay, as for example when providing air mass compensation when the selector lever is moved from N to D or torque limitation in connection with gear changing.

All information sent out on a bus by a control module is available to all other control modules connected to the bus. The MIU ensures that the information which is available on one bus is also available on the other.

The control modules send out information on the bus at regular intervals. The time between two transmissions depends on the information being sent and varies between 10 milliseconds (0.010 seconds) and 1 second. Information is also sent out by the control modules whenever the information changes.

The transfer of information between the control modules takes place on two leads, bus+ (green lead) and bus- (white lead). The leads are twisted to reduce susceptibility to electrical interference.

SID uses the following information

Information

Values

From

The value depends on the following sensor input, signal or function

Position light

ON/OFF

DICE

Right rear light or Left rear light (bus value from TWICE). The SID uses the information when calculating the rheostat value.



Rear fog light broken

YES/NO

DICE

Control module current measurement of output to lamp. The SID uses the information for CHECK messages.



LH direction indicators

ON/OFF

DICE

Control module activation of output to lamps. The SID activates TICK-TOCK for the direction indicator function.



RH direction indicators

ON/OFF

DICE

Control module activation of output to lamps. The SID activates TICK-TOCK for the direction indicator function.



Sound

Sound information

DICE, TWICE, ACC, Audio, MIU, PSM, Trionic, SPA



The SID activates the type of sound that has been requested via the bus.

Left rear light broken

YES/NO

TWICE

Control module current measurement of output to lamp. The SID uses the information for CHECK messages.



Right rear light broken

YES/NO

TWICE

Control module current measurement of output to lamp. The SID uses the information for CHECK messages.



Left Brake Light Faulty

YES/NO

TWICE

Control module current measurement of output to lamp. The SID uses the information for CHECK messages.



Right Brake Light Faulty

YES/NO

TWICE

Control module current measurement of output to lamp. The SID uses the information for CHECK messages.



High Level Brake Light Faulty

YES/NO

TWICE

Control module current measurement of output to lamp. The SID uses the information for CHECK messages.



Brake lights

ON/OFF

TWICE

Brake light switch



Horn

0 : 6 : 42 ms

TWICE

Anti-theft alarm function and central locking system function. The SID uses the information from TWICE and activates the horn for the requested time in ms as acknowledgement of “TSL” locking.



Text message

Text information

TWICE, ACC, Audio, Trionic, TCM, SPA

Anti-theft alarm function and central locking system function. Text information from TWICE concerning the anti-theft alarm function, from ACC concerning user programming, audio display and high transmission fluid temperature warning.



RDS time

Hours, Minutes, Seconds



Audio

RDS reception. The SID uses the information for the time function (the clock).



RDS date

1-31

Audio

RDS reception. The SID uses the information for the time function (the clock).



RDS month

January - December

Audio

RDS reception. The SID uses the information for the time function (the clock).



Vehicle speed

km/h, mph

MIU

Rear left wheel speed. The SID uses the information for calculations for the trip computer function.



Fuel level

litres

MIU

Tank sensor, control module adjustment. The SID uses the information for calculations for the trip computer function.



Odometer reading

km, miles

MIU

Display value. The SID uses the information for calculations for the trip computer function.



Fuel consumed since start

0- 65535 ml

Trionic

Fuel injection function. The SID uses the information for calculations for the trip computer function.



Engine Started

ON/OFF

Trionic

Crankshaft position sensor. The SID uses the information to calculate “Engine off time”.



Coolant temperature

-40 - 215°C

Trionic

Coolant temperature. The SID uses the information for calculations for the trip computer function.



Diagnostic communication



DICE

Control module must be live and the bus leads intact. See Bus and diagnostics communication .







The SID sends out the following information

Information

Values

Used by

The value depends on the following sensor input, signal or function

Info Disp Lamp

ON/OFF

MIU

In connection with text message. The MIU lights the lamp on request from the SID.



Unit

Metric, Imperial (°F), Imperial (°C), US

ACC

The unit that has been selected with the button.



Language

English, German, French, Italian, Swedish, Spanish

ACC

The language that has been selected with the button. The SID transmits information about which language has been selected.



Steering wheel controls

VOL -, VOL +, SRC, SEEK >>, << SEEK, NXT



Audio

Button control module input. SID sends information when a button is pressed (activated) on the steering wheel controls. Applies if the car has the Saab Audio System.

Rheostat level

0- 100%

Audio, ACC, DICE, MIU



Rheostat control module input. SID transmits the data for regulating instrument and control lighting.

Rheostat Night Panel

0- 100%

Audio, ACC, DICE, MIU



Rheostat control module input reduced by a fixed value. Used for button illumination.

Night Panel

ON/OFF

Audio, ACC, DICE, MIU



Button. The Night Panel function is activated and deactivated.

CLEAR

ON/OFF

SPA



Button.

Display lighting

0- 100%

ACC, MIU



Lighting level for all displays. The highest value of the rheostat control module input or light sensor.

Light intensity in the car

Lux

MIU

Light sensor. Used by MIU to control the intensity of indicator lamps.



Engine Off Time

Minutes

ACC

+15. ACC uses the value to calculate the settings when starting.



Outside temperature

°C

ACC, TWICE, DICE



Outside temperature sensor, control module adjustment. SID transmits information for use by other systems.

Diagnostic communication

-

DICE

Control module must be live and the bus leads intact. See Bus and diagnostics communication .