[wb4suv]

A few others have posted here that they have been successful at getting a used BCM reprogrammed for their car. I purchased a used BCM on www.car-part.com for $400 and took it to my Honda dealer today with high hopes of getting my car back on the road. I paid the dealer $190 to try but they were unsuccessful. The mechanic said he tried three different approaches without success.
I asked the mechanic if they used a third party in the process and he said yes that all Honda dealers do because the program is proprietary. He said the only possibility is to find someone with a “Smart Pro or Top Gun programmer” to reprogram it. These programmers have the ability to turn off safety features which is why a dealer will not have one. I did an internet search and could not find anything but key reprogrammers.
Talked to the parts department and they said they have 11 BCM’s on order for customers and one has been on order since October 2021.
Upon leaving I had to take the battery cable off three times resetting the BCM to get the car to start.

 

[Butigli]

I think the fuel monitor thing can be if the sensor is being messed with like mine does it when I get to the 1 gal mark and go up or down a hill (we have some steep hills in KY) My old car did it too, so I think it is the sensor being touched as you level out and is normal. though I am a PC technician NOT an automotive engineer. My gas mileage has been noticeably reduced since I am connecting/disconnecting battery, which may be because I have to remember each time everything comes back up to push the econ button, I am used to leaving it on...and I was like "I can't see the battery drain effecting the mpg...???" but once I put a little thought into it, I noticed the econ indicator isn't on. these units must be a real pain to get to, I hope Honda considers that when they design another. working on PCs I know that some parts just need to be accessible so you can do something like unplug and plug back as a first step of troubleshooting. sorry to go on... guess I have had too much caffeine this morning 😁

I am not sure if mine is the BCM or the wiring to the BCM, as when I reconnect and hold the audio on button for 2 sec everything comes back up and seems to work as it did before the drain, I can still let it pretty much drive it's self, just like before the drain. it just makes me worry that replacing the BCM may not do the trick...or maybe it will get the bad connection that is draining my battery reseated and connected properly. So to me it seems like the computer works but Honda is not investigating all of the issues that may be involved...for example is it a cable that is hard to get to and just needs to be reset, and Honda is not training the service center technicians to do it ...or not telling the service center tech to do it? Yet they are offering to purchase these vehicles... Sorry for expressing frustration, but theses vehicles cost an annual salary around here, you get it paid off and then it doesn't work properly. moving to complaint site

 

[HelpfulBrother]

Question for those who unplug backup fuse. Does that just kill power to the BCM? I can see that as a better solution then disconnecting the battery which was a solution I thought about doing. If the backup fuse kills power to the BCM but not the ECM I’m sure that would be beneficial to the vehicle.

 

[TheDarkKnight]

Yet they are offering to purchase these vehicles

And why shouldnt they?

Sick of telling people - the issue is NOT Honda's. Its a supplier to Honda. Take out your emotions when responding - last warning, or I will nuke this thread.

 

[Jayceegee]

And why shouldnt they?

Sick of telling people - the issue is NOT Honda's. Its a supplier to Honda. Take out your emotions when responding - last warning, or I will nuke this thread.

I think that 99.9% of the people understand that Honda is not to blame but rather the supplier. Please don't nuke this discussion because of the the very few who do not get it. I think this site is helping most. Thank you

 

[TheDarkKnight]

Please don't nuke this discussion because of the the very few who do not get it. I think this site is helping most.

Agreed.

But any else who posts any over-emotional posts hereon in will be summarily removed entirely without warning/notice so as not to damage the thread which, as you rightly note, contains some helpful information

 

[2019CRVDriver]

I think the fuel monitor thing can be if the sensor is being messed with like mine does it when I get to the 1 gal mark and go up or down a hill (we have some steep hills in KY) My old car did it too, so I think it is the sensor being touched as you level out and is normal. though I am a PC technician NOT an automotive engineer. My gas mileage has been noticeably reduced since I am connecting/disconnecting battery, which may be because I have to remember each time everything comes back up to push the econ button, I am used to leaving it on...and I was like "I can't see the battery drain effecting the mpg...???" but once I put a little thought into it, I noticed the econ indicator isn't on. these units must be a real pain to get to, I hope Honda considers that when they design another. working on PCs I know that some parts just need to be accessible so you can do something like unplug and plug back as a first step of troubleshooting. sorry to go on... guess I have had too much caffeine this morning 😁

I am not sure if mine is the BCM or the wiring to the BCM, as when I reconnect and hold the audio on button for 2 sec everything comes back up and seems to work as it did before the drain, I can still let it pretty much drive it's self, just like before the drain. it just makes me worry that replacing the BCM may not do the trick...or maybe it will get the bad connection that is draining my battery reseated and connected properly. So to me it seems like the computer works but Honda is not investigating all of the issues that may be involved...for example is it a cable that is hard to get to and just needs to be reset, and Honda is not training the service center technicians to do it ...or not telling the service center tech to do it? Yet they are offering to purchase these vehicles... Sorry for expressing frustration, but theses vehicles cost an annual salary around here, you get it paid off and then it doesn't work properly. moving to complaint site

Yeah I also kept forgetting to press the Econ button which surprisingly makes a big difference on the MPG rate. I wish that info got saved in the non-volatile memory, it's so easy to forget to press it.

I spoke to two Honda techs about this and they mentioned that it could certainly be a wiring issue since the BCM operates fine once the battery is reconnected, and it's unlikely the BCM is "fried". But they mentioned that most techs default to replacing the entire BCM without looking any further, probably due to lack of experience or instruction with this issue. Also just heard from my dealership's parts department. My order got pushed from June 8 to July 8 just like yours; was told this is common now and will likely happen a few more times until the part actually arrives. The wait continues.

Question for those who unplug backup fuse. Does that just kill power to the BCM? I can see that as a better solution then disconnecting the battery which was a solution I thought about doing. If the backup fuse kills power to the BCM but not the ECM I’m sure that would be beneficial to the vehicle.

If you unplug the backup fuse, would you still be able to control certain components like the power windows?

 

[wb4suv]

For those disconnecting the battery continuously I suggest just loosening the negative terminal clamp and just twisting it on and off by hand. Taking the number 18 fuse out works just as well but could cause the fuse holder to lose its grip on the fuse after numerous in and outs.
Disconnecting battery shortcut, I performed
REPEAT AT YOUR OWN RISK
I ran a pair of wires from the fuse box to a switch in the car where I can essentially flip the switch and not have to raise the hood. This was not as hard as I thought it would be. In the engine compartment on the passenger side, I was able to push a piece of #14 wire next to the wire bundle into the passenger compartment. Reach up behind the glove compartment and pull enough wire to make a splice. I then twisted and taped a piece of lamp cord to the #14 wire in the passenger compartment and pulled it into the engine compartment.
Now the hard part.
1 Disconnect the battery
2 pull the #18 fuse and put it in fuse box lid
3 Take a fuse of the same physical size and sand the back side to expose the metal (The smaller amperage the better)
4 Pick and file the plastic to expose a little more metal
5 Solder a 4” wire to each of the exposed pieces of metal on the back of the fuse
6 Connect the wires soldered to the fuse across a battery to blow the fuse
7 Connect an in-line fuse holder with a 10-amp fuse to one of the wires in the engine compartment and the other fuse holder wire to the blown fuse
8 Connect the remaining wire to the other side of the blown fuse.
9 Install a single pole light switch to the wires in the driver's compartment
10 Install the blown fuse with wires connected into fuse socket 18
11 Reconnect the battery.
I can now flip the switch and not have to raise the hood. Caution accidently flipping the switch while driving will stop the engine which could be dangerous

Question for those who unplug backup fuse. Does that just kill power to the BCM? I can see that as a better solution then disconnecting the battery which was a solution I thought about doing. If the backup fuse kills power to the BCM but not the ECM I’m sure that would be beneficial to the vehicle.

Unplugging the fuse over and over will probably destroy the fuse holder

 

[williamsji]

For those disconnecting the battery continuously I suggest just loosening the negative terminal clamp and just twisting it on and off by hand. Taking the number 18 fuse out works just as well but could cause the fuse holder to lose its grip on the fuse after numerous in and outs.
Disconnecting battery shortcut, I performed
REPEAT AT YOUR OWN RISK
I ran a pair of wires from the fuse box to a switch in the car where I can essentially flip the switch and not have to raise the hood. This was not as hard as I thought it would be. In the engine compartment on the passenger side, I was able to push a piece of #14 wire next to the wire bundle into the passenger compartment. Reach up behind the glove compartment and pull enough wire to make a splice. I then twisted and taped a piece of lamp cord to the #14 wire in the passenger compartment and pulled it into the engine compartment.
Now the hard part.
1 Disconnect the battery
2 pull the #18 fuse and put it in fuse box lid
3 Take a fuse of the same physical size and sand the back side to expose the metal (The smaller amperage the better)
4 Pick and file the plastic to expose a little more metal
5 Solder a 4” wire to each of the exposed pieces of metal on the back of the fuse
6 Connect the wires soldered to the fuse across a battery to blow the fuse
7 Connect an in-line fuse holder with a 10-amp fuse to one of the wires in the engine compartment and the other fuse holder wire to the blown fuse
8 Connect the remaining wire to the other side of the blown fuse.
9 Install a single pole light switch to the wires in the driver's compartment
10 Install the blown fuse with wires connected into fuse socket 18
11 Reconnect the battery.
I can now flip the switch and not have to raise the hood. Caution accidently flipping the switch while driving will stop the engine which could be dangerous

View attachment 155948 View attachment 155949


Unplugging the fuse over and over will probably destroy the fuse holder

Yep, those fuse box connectors are not made for daily removal/insertion of fuses. You probably can get about 100 cycles before the fuse socket connections degrade and become unreliable. Normally this is fine, because on average fuses don't get pulled/inserted in any slot more than one or two times over the life of the vehicle. The main form of degradation is friction removal of the tin coating in the fuse socket connections. Once that happens, you are down to exposed copper which will oxidize in place in a warm engine compartment and create poor connection issues.

Since we know removing fuse 18 will stop the BCM malfunction from draining the battery, if dealing with this every day, your approach to placing a switch in the fuse 18 line is a workable solution, though probably fraught with possible negative consequences if the owner does not actually understand what they are doing, why, and how.

So I agree with your approach, though I advise caution to any owner is not electronics and wiring savvy. Your instructions appear clear to me, and safe if you know what you are doing.

As for the use of a switch, yeah I would make sure that switch is somewhere where it cannot get accidentally switched off while driving, because as you noted that may turn off the vehicle while you are driving and in motion.

 

[williamsji]

So I looked up the BCM at parts sites online. There are actually a range of different units and part numbers, and some are model year specific. They all share the same physical profile, so variations are likely just electronic or programming in nature.

Here is my real point though... there are a bunch of connectors on these BCMs, which makes sense given how many different systems in the vehicle they touch. As an old school electrical engineer, who has faced numerous squirrel behaviors from electronics directly related to poor cable harness connections to connectors, I have to wonder if some of what is being seen here is simply poorly seated harness connectors to the BCM itself. Keep in mind, our vehicles do get bumped and jostled around from daily driving, so it is quite possible some reports of issues are not the actual BCM but connections to the BCM.

I am mindful that first there were only a few reported, but as time goes on, we are seeing more reported bad BCMs. Electronically speaking, time based issues like this smacks of "check your connections to the unit".

I don't know this objectively to be a cause here, but it is logical to at least suspect it and reseat the connectors. I have no idea if Honda workflows for troubleshooting the BCM include checking and re-seating connections before replacing. But if I had a BCM issue right now, facing the long back order for the component, I would at least try re-seating the connections as that may solve some owners issues. Or it may not... but no harm in trying.

Note: this it not say there are not some bad BCMs in the field, only that the cable connections should be suspected and confirmed good if having this issue.

 

[wb4suv]

So I looked up the BCM at parts sites online. There are actually a range of different units and part numbers, and some are model year specific. They all share the same physical profile, so variations are likely just electronic or programming in nature.

Here is my real point though... there are a bunch of connectors on these BCMs, which makes sense given how many different systems in the vehicle they touch. As an old school electrical engineer, who has faced numerous squirrel behaviors from electronics directly related to poor cable harness connections to connectors, I have to wonder if some of what is being seen here is simply poorly seated harness connectors to the BCM itself. Keep in mind, our vehicles do get bumped and jostled around from daily driving, so it is quite possible some reports of issues are not the actual BCM but connections to the BCM.

I am mindful that first there were only a few reported, but as time goes on, we are seeing more reported bad BCMs. Electronically speaking, time based issues like this smacks of "check your connections to the unit".

I don't know this objectively to be a cause here, but it is logical to at least suspect it and reseat the connectors. I have no idea if Honda workflows for troubleshooting the BCM include checking and re-seating connections before replacing. But if I had a BCM issue right now, facing the long back order for the component, I would at least try re-seating the connections as that may solve some owners issues. Or it may not... but no harm in trying.

Note: this it not say there are not some bad BCMs in the field, only that the cable connections should be suspected and confirmed good if having this issue.

When I pulled fuse 18 I noticed that where the actual connection was making contact which was a thin shiny line to each side of the line the fuse spade was dark as if it had been hot. I checked several other fuses which did not show any discoloration. If there was an over current it would have blown the fuse. While it appears to be making a good connection it still concerns me.
Would love to hear from others with a BCM problem if their fuse displays the same thing.
Possibly a root cause!

 

[Jayceegee]

When I pulled fuse 18 I noticed that where the actual connection was making contact which was a thin shiny line to each side of the line the fuse spade was dark as if it had been hot. I checked several other fuses which did not show any discoloration. If there was an over current it would have blown the fuse. While it appears to be making a good connection it still concerns me.
Would love to hear from others with a BCM problem if their fuse displays the same thing.
Possibly a root cause!

My thoughts are to get a new fuse and see if that helps or at least see if the dark lines return. Happy trails to you

 

[Krishanth V]

Greetings to all.

The body control module in my CRV 2018 (RW1) VTI- L has become faulty. It automatically switches on the instrument cluster and the immobilizer after the vehicle is locked. This issue keeps draining the vehicle's battery. It is an Australian spec and the vehicle is currently in a country called Sri Lanka. I'm unable to get it repaired at the local Honda dealership as they informed me that they will not be able to import the part due to the economic issues Sri Lanka is facing right now. The part number in my vehicle is 38800-TLA-Q312-M1. Checked with Honda Australia asking for a quote and they did provide a quote with a different part number 38809TMMQ31 for my VIN. Do you think this would fit my vehicle?

Please HELP

 

[2019CRVDriver]

So I looked up the BCM at parts sites online. There are actually a range of different units and part numbers, and some are model year specific. They all share the same physical profile, so variations are likely just electronic or programming in nature.

Here is my real point though... there are a bunch of connectors on these BCMs, which makes sense given how many different systems in the vehicle they touch. As an old school electrical engineer, who has faced numerous squirrel behaviors from electronics directly related to poor cable harness connections to connectors, I have to wonder if some of what is being seen here is simply poorly seated harness connectors to the BCM itself. Keep in mind, our vehicles do get bumped and jostled around from daily driving, so it is quite possible some reports of issues are not the actual BCM but connections to the BCM.

I am mindful that first there were only a few reported, but as time goes on, we are seeing more reported bad BCMs. Electronically speaking, time based issues like this smacks of "check your connections to the unit".

I don't know this objectively to be a cause here, but it is logical to at least suspect it and reseat the connectors. I have no idea if Honda workflows for troubleshooting the BCM include checking and re-seating connections before replacing. But if I had a BCM issue right now, facing the long back order for the component, I would at least try re-seating the connections as that may solve some owners issues. Or it may not... but no harm in trying.

Note: this it not say there are not some bad BCMs in the field, only that the cable connections should be suspected and confirmed good if having this issue.

Is there anywhere I can find instructions on how to properly re-seat the connections to the BCM for my vehicle? or does it require a Honda tech to do it in the sense that there could be security codes or something that need to be entered? My BCM issues happened after a collision so I wonder if the vibrations shook the connections somewhere.

Also I learned that all the BCMs are generally identical in terms of hardware. What differs is the firmware that gets flashed onto it since different trims/models have additional hardware components (sunroof vs. no sunroof) that require software. Can't confirm if this is actually true though, heard it from a master tech on a different forum.

 

[Traylaw]

Nothing special about unplugging and reseating the connectors. Just disconnect the negative cable on the battery first. The other items programmed into the BCM are the ident codes for your FOBs so it will recognize them and the PCM is programmed to recognize the identity of the BCM. It's all part of the immobilizer scheme.

 

[williamsji]

Upset with Honda after being told my part order was put on emergency list, and since it is not produced until ordered (early April) it will be delivered on June 8. Call American Honda last week to verify on schedule, I am told yes. Call local Honda to schedule install on June 9, done. Got text this morning it is now going to be July 8 before part delivery. The work around I came up with, and Honda Service approved, is to disconnect battery every time I turn off car for more than a few minutes. It is a pain but I am a hardware tech by trade so for a few weeks I have been okay. But now I'm wondering if this is just going to go on for ever. My husband's distaste is such that he will never buy another Honda. IDK if the techs even unhooked and plugged each connection back in, I would do it myself if I new how to get to the BCM. I know of at least 10 other CRVs having this same issue, and those cars are just sitting, I can't afford that after paying a years salary for a vehicle, or have my husband cart me around...no way...I bought this car and I want to use it it should last longer than 5 years, like my Nissan did, and my husband's Toyota has. Now I have to go to a wedding 500 miles away this weekend and leave my car totally unsecured in a very large city I'm not familiar with. I am upset my car is not being fixed in the time indicated by Honda service, and that this issue seems to be being ignored by Honda.

P.S. 2 months ago I felt like Honda was ignoring this issue. But was willing to give them a shot. I think the local people are doing what they are allowed. But big Honda needs to address the issue for us, and make the unit easier to service in the future. A unit with that many plugs needs to be accessible.


Oh...and I also think a consumer watch
service will be informed.

I get that you are frustrated, but your emotional expressions here are not helpful to the discussion. All you are doing is making more work for the forum moderation team with this.

By all means discuss the topic, rather than railing on Honda over the issue. Honda does not produce the BCM, they buy them from a 3rd party supplier, as is true with many components in modern motor vehicles. And sadly, supply chains are a mess right now due to prolonged impacts to production due to COVID.

 

[williamsji]

Is there anywhere I can find instructions on how to properly re-seat the connections to the BCM for my vehicle? or does it require a Honda tech to do it in the sense that there could be security codes or something that need to be entered? My BCM issues happened after a collision so I wonder if the vibrations shook the connections somewhere.

Also I learned that all the BCMs are generally identical in terms of hardware. What differs is the firmware that gets flashed onto it since different trims/models have additional hardware components (sunroof vs. no sunroof) that require software. Can't confirm if this is actually true though, heard it from a master tech on a different forum.

Physically all the Honda BCM variants do look the same. Yes, I imagine the different part numbers are simply different firmware versions (to align with the actual features for the trim level of the vehicle). Part numbers would also be different if the supplier is different (normal Honda practice, and one reason why Honda has so many different battery part numbers too, for the same size battery).

As for reseating the connectors, I have not checked under my dash to see if I can access the BCM without any disassembly, but I trust Traylaw when he makes recommendations, so follow his guidance above. Just be mindful to not get in over your head, and if in doubt, leave it alone or you may make matters worse.

 

[wb4suv]

I have seen numerous comments where people are frustrated about not being able to lock their car with the bad BCM. I lock the doors while open and then close them locked. I then use the key inside the FOB to unlock the door

 

[HelpfulBrother]

Yep, those fuse box connectors are not made for daily removal/insertion of fuses. You probably can get about 100 cycles before the fuse socket connections degrade and become unreliable. Normally this is fine, because on average fuses don't get pulled/inserted in any slot more than one or two times over the life of the vehicle. The main form of degradation is friction removal of the tin coating in the fuse socket connections. Once that happens, you are down to exposed copper which will oxidize in place in a warm engine compartment and create poor connection issues.

What are your thoughts about using a fuse tap? Rather then unplugging the fuse directly from the slot I would remove it from fuse tap. That way it would be less wear on fuse slot 18 in the car and I could replace the fuse tap once it didn’t seat tightly anymore.

 

[wb4suv]

In theory that could work but as tight as the fuses are I think you would wind up unplugging the fuse tap from the original fuse holder or wiggle it enough to still cause damage. A fuse tap could also be used and install a switch as I described above to save soldering wires to the fuse but you would really have to fully understand what you were doing and derive the power source directly from the battery with proper orientation of the fuse tap which I would not even attempt to describe how.