I'm the original owner of a 13' CX5 and believe that my RBCM may have been inadvertently damaged. Cargo light was out so I went to replace the bulb and there was a small spark. When the new bulb failed to work I tested the leads & there was no power. I searched some sites to i.d. what the problem may be and found out that this cargo light is directly connected to the RBCM without an intervening fuse; what electrical engineer made this design? I next noticed some errors in the data displayed for the fuel tank level, mpg, and other readouts, but all other lights, door locks, windows, camera, etc. work as expected. I called the dealer but they would not even provide any guidance without me bringing the car in and paying them for an evaluation & repair. I do believe its the RBCM based on the issues present & can replace it myself, but I do have two questions:

1: If I disconnect the battery on the exisitng unit, is it possible the RBCM will reset itself & work properly, or once gone, its gone?
2: Does the new RCBM require any special programming, or is it basically a plug & play device that once energized, will sync with the car's computer systems?

Thanks.......

 

You can definitely try disconnecting the battery for 10-15minutes. ( Make sure the cargo bulb is the correct type and correctly fitted )

BCMs, FBCMs, & RBCMs are all specifically coded for the individual vehicles.

 

Grim Reaper, thanks for the response. I gave it a try this morning, but no luck. Cargo light is still out and the fuel gauge & other fuel related read-outs continue to be contradictory and erroneous. Looks like I'll be buying a new RBCM this coming week. I actually found a few used units for sale, but quite honestly the cost differential is not worth the risk of failure with an old module.

 

An update: Mazda apparently issued a service memo about the issue of a cargo bulb shorting out the RBCM; there's no repair here, only replacment of the module. And I spoke with a Mazda specialist who confirmed that any new RBCM will need to be programmed to match the settings of the original RBCM. Its not plug & play and requires attachment to their diagnostic system & reprogramming at a Mazda center. Moral of the story with CX-5's & maybe with other Mazda's: disconnect the battery for even the most insignificant of issues such as replacing an interior bulb.

 

As an update: Mazda confirmed that the RBCM is not plug & play and that the car needs to be connected to their diagnostics system to read the original module and then reprogram the new unit to match original settings. Not what I had hoped for but that's the way it is so car will go into the dealership as soon as the new module is received.

 

Use Forscan (free) and a ELM327, it's easy to reprogram the module.
If you lost all RBCM code you can get it back by entering your vehicle VIN number in this page: AsBuiltSearchPage RBCM code is in 7B7 section.

 

Hi, I have had an issue also with the rear BCM. 2013 2.2 NavSport 170.

My battery went flat back at the start of the year after being away for a month. Even after fully charging, the car was slow to turn over in winter and so I decided to go for a new stop start battery.
Following this, I started to get issues. First was intermittent working of the rear camera which then failed completely.
Then the city braking warning light came on.
Since then, the following have also failed / come up one by one:
Air bag warning on
Keyless system check required
Braking check required
Reversing sensors failed
A/C controls seem to have changed (mn 18 degs instead of 15)
Rear tailgate won't open
Fuel gauge (sensor?) stopped working and constant refill light on.

I popped into my local mechanic and he ran a check and was getting " No communicatiin with BCM"
A quick look on Mazdas website shows al these are linked to the rear BCM module.
I have taken off the rear quarter inner panel and got to the BCM. I thought initially it may be rodent damage or similar but all is clean and no signs of damage. I assumed the BCM is breaking down in some way?

I've ordered a second hand BCM with same part number from the same model car. What are the chances of this just Plug and playing or will it be a reprogram?

TIA for any assistance

 

It should work if RBCM it's from the same model and trim, ask second hand part vendor if he can provide VIN number from donor part.
In my earlier post I linked an AsBuilt search, enter VIN for both cars download and compare asBuilt 7B7 section, they should be identical.

 

Thanks, I have managed to get one complete with original VIN so can cross check. Fingers crossed. Thanks again.

 

Hi, I've just had a quick look at my codes against the replacement BCE codes for the unit I have purchased. All are identical except the following:

BCE Module settings
OURS / REPLACEMENT:
720-01-01 A323 79A6 808E A32379A6808D
720-01-02 B2F7 0900 00DC
720-01-03 0000 0000 002B
720-01-04 0000 0000 002C
720-01-05 0000 0000 002D
720-01-06 0000 002E
726-01-01 F240 016E 5828
726-01-02 64AA D354 56BB
726-01-03 52AA AAA6 7D
731-01-01 0814 E024 207A 0814 E024 209A
731-01-02 1800 1E47 9048 180C 1E47 9054
731-01-03 0220 005E
737-01-01 AAF3 DDBD C138
737-01-02 80DE 8726 7
B7-01-01 9D52 0006 E196
7B7-01-02 8701 D300 0824 A501 D300 0842
7B7-01-03 0018 9000 6A

I have downloaded Forscan and have an ELM327 adaptor. How easy is it to reprogram these 4 rows?

Thanks in advance again!