Bus communication
Bus communication |
• |
Control module ACC (216)
|
• |
Radio connector C (267c)
|
• |
Control module airbag/SRS (331)
|
• |
Radio (353)
|
• |
CD changer (355)
|
• |
Control module PSM (357Dk)
|
• |
Trionic T7 control module (430b)
|
• |
Transmission control module, TCM (502b)
|
• |
MIU (540d)
|
• |
SID (541)
|
• |
Control module, ABS (547)
|
• |
Control module STC (565)
|
• |
Trionic T7 OBDII control module (589b)
|
• |
Control module, DICE (628)
|
• |
Control module, TWICE (632)
|
• |
TC/ABS (382)
|
Bus communication, diesel EDC 15 |
• |
Control module ACC (216)
|
• |
Radio connector C (267c)
|
• |
Control module airbag/SRS (331)
|
• |
Radio (353)
|
• |
CD changer (355)
|
• |
Control module PSM (357Dk)
|
• |
MIU (540c)
|
• |
SID (541)
|
• |
Control module, ABS (547)
|
• |
Control module STC (565)
|
• |
EDC 15 control module (595)
|
• |
Control module, extra heater (597)
|
• |
Diesel pump (598)
|
• |
Control module, DICE (628)
|
• |
Control module, TWICE (632)
|
Bus communication, diesel PSG 16 |
• |
Control module ACC (216)
|
• |
Radio connector C (267c)
|
• |
Control module airbag/SRS (331)
|
• |
Radio (353)
|
• |
CD changer (355)
|
• |
Control module PSM (357Dk)
|
• |
MIU (540c)
|
• |
SID (541)
|
• |
Control module, ABS (547)
|
• |
Control module STC (565)
|
• |
Fuel pump with PSG 16 control module (595)
|
• |
Control module, extra heater (597)
|
• |
Control module, DICE (628)
|
• |
Control module, TWICE (632)
|
P-bus and I-bus |
By bus is meant leads in which information is transmitted digitally and serially. By digital is meant that the voltage difference between the two leads can have only two values, approx. 0 and 5 V. The information is coded so that different combinations of pulses with the values 0 and 5 V mean different things.
Serial means that the information is sent in ”packets” one after the other in rapid succession.
The buses consist of a P-bus (Power-train 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.
As in the 9-5, the Airbag and ABS control modules are not bus-connected.
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 transmission rate of the P-bus is ten times greater than that of the I-bus. The reason for this is that the power-train system requires information with the minimum possible delay.
All the information sent from one control module is accessible for all other control modules on the bus. The MIU is responsible for ensuring that information available on one bus is also available on the other bus.
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.
Transmission of information between control modules occurs on two leads, bus+ (green lead) and bus- (white lead). The leads are twisted to increase tolerance to electrical interference.
TWICE uses the following information for the theft protection |
TWICE sends the following information for the theft protection |