Where do you "ground" B-can in Honda?
I am diagnosing a parasitic drain. Fuse 29 “back-up" is the circuit that is causing this drain. Honda diagnostics for a parasitic drain gets me to the step that says to:
Short the B-CAN line to body ground with a jumper wire while test leads are connected.
This is to prove if it is a can failure or something else. So I have very little knowledge of networking and am lost on where the best place to ground this is, and I assume I am grounding the CAN-B positive?
So for the questions on where I got the information. It is located in Direct Hit under symptom and repair information. Then under wiring system, then measurement of parasitic draw. Attached is the complete diagnostic procedure and the diagram for B-Can and wiring diagram for fuse 29.
If you ground either CAN wire you are grounding it for the entire network so pick the easiest spot to access. I went looking for this in Honda Service info to get some clarification but I could not find anything. Can you share the service info where it says to do this? This is a new one for me.
Richard, there are two types of low-speed CAN buses: single-wire and fault tolerant two-wire. Grounding only one wire in the fault tolerant bus is not going to bring down the network (even though modules will notice that and complain), see the highlighted paragraph: diag.net/file/f6qmhgzlv… The question is whether Honda’s B-CAN for that car is the fault tolerant one…
Dimitri, I agree 100% and that’s why I was asking to see where in-service information Honda was telling him to ground a can wire. Something doesn’t seem right
It’s probably instructions for the previous generation, which used a single-wire CAN. Will wait for Craig to double-check.
Attached is the parasitic draw testing document for 12-13 model years. maybe 2012 was a single wire body bus? But it does say ground B can. Strange.
Very strange indeed! There are documents like this on the Internet as well, but I am not sure which year this is for: diag.net/file/f1v44w2r6…
Thank you for the update, Craig! This is a two-wire CAN, so grounding just one wire will not be enough. Could you look up the same procedure for 2014 car and check if they updated the manual? If that one would not clear things up, try grounding both wires, or shorting them together.
I checked the year older information for this and it says to short the b-can high and low wires together with a jumper. I will be doing that tomorrow and see what I get.
Ok that makes much more sense. With both wires shorted to eachother there will be no communication and All of the B can modules should not wake up.
My understanding is I am shorting out the b-can controllers and seeing if drain stays or goes away. I think I am trying to find out if it is a module or an input to controller causing drain.
Hi Craig Yes Follow the f29 feed and wherever it feeds to others in the circuit.
Thanks for replies. So with this issue I ended up going a different direction. I noticed that security was acting strange. When locking with key fob the security light on dash would not turn on. After checking this for a bit I found that key would not turn driver's door key cylinder. Someone tried to break into car and broke the key sensor in lock actuator. Replaced actuator and key…