between the B-can and C can not change the R internal why? the first ecu and the ecu will always have the R closure 120 ohm, it will only change the speed? data transfer (C) can 10 kbps to 125 kbps and C can from 125 kbps to 500 kbps)...obviously I was wrong to indicate 120 ohms as the total value why? really? ? 60 ohms (R in parallel) so if you measure ir? of 60 ohms or 120 ohms c ? a communication problem.Originally Written by Backgroop
sorry carma, practically out, for example, the comb of the ecu and in the moment that makes me the error between the pin 83 and 84 of the ecu, the engine would have to find or 60 or 120ohm resistance??? or do I need to measure with the comb attached and the ignition is on??? sorry..... and how to distinguish the b can c can?? where runs the b and where runs the c can.... however, I was checking now.... and despite the fact that the airbag light turns on and off easily at the time of the power on.... I'm not supposed to find the ecu is active on the line??? I find it not as present as I asked all the controllers connected....
not ? important to know if ? A can B can C can-why? the R sealing ring are 120 ohm....among the various families of the network can only change the speed? data transfer and there? for which they are implemented.
the measurement is with the ignition switched off...but I don't know if the R of the closure may be in the wiring or internal to the ecu (I believe in the wiring to distinguish the first ecu from last)...with 2 R in parallel with 120 ohm resistance the final measured must? be 60 ohms
The network that are interested in this case and the C-can, which connects the body computer to the engine control unit and ABS, the resistors are internal to the control units are not integrated to the harness, the measure of 60 ohms must be a closed network without disconnecting anything.. in practice, it must be measured the resistance between the green wire and brown on the body or on the ccm.. another test to do, and test the voltages of the network with reference to ground this framework, on, with everything connected.. to the voltage of the can-H and can-L) with reference to ground must be equal to +- 2.5 v .. on that car ? also, there is a network W, this network works in case of emergency so that the can bus has a problem..
The patience and virtue of the strong..
on Can networks-C and we have a value of 60 Ohms because the termination resistors are 2 120 Ohm placed in parallel and the architecture of their connection to the result if the functional sar? 60 Ohm resistor..
thanks to all for the interest..... then... here is resolved, what is the line w..... virtually how to get it ? a safety line if it does not work the can line... pretty much guys.... tonight I noticed one thing....
practically, after having heated the engine.... back in the workshop, the car after 5 minutes, as usual, presented the usual problem.... the ecu's you can find all ok, the engine control unit does not activate... in the engine diagnosis I log in, but I don't see anything, as if the ecu is active.... but frozen....
if, instead, the car does the check and ? everything is ok, by quietly, diagnosis can the engine control unit found active, the diagnosis engine all ok....
I want to do the last tests to measure all the values of the can line, but to measure the resistance with the controllers connected, I have to strip the wires of the can bus??
yesterday, after 1000 trials.... we came to the conclusion... the problem lies in the ecu of the engine....
we measured the can line to the oscilloscope and everything ? ok, the power supply and the masses are ok...
now I am looking for a ecu 0 281 011 511
I often? I try to find it on www.cercaricambi.it
Write permission
Quote