Expert: Roland Finston - 11/5/2011

Question
QUESTION: i've been told my BCM is probably bad. have read how to replace it myself but saw another post that said it has to be reprogrammed after installation. is that true or can i go ahead & install it myself? thanks for your time.

ANSWER: Hi Dee,
If you have the vehicle theft security system there is a routine that you need to go through to set that up to work again. There may be some other features that are optional and which would similarly have to be set up to gain the use of them. But in general there is nothing that would stop the vehicle from running except if the theft system were not properly addressed according to the procedure.
But my first question is: what basis do you have in believing that you must replace the body control module?  Let me know the history of that problem.
Roland

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QUESTION: ok. as i was driving down the road one day, my a/c fan just stopped blowing. the fan itself doesn't work. also the blinkers, the rear windshield wiper, the digital compass all don't work. note- my hazards & front wiper still work.  also the check engine soon light, abs light, and air bag lights are now on all the time. i've had it hooked up to a computer & it says there's nothing wrong...it was reset afterwards & everything is still off. we have also checked all of our fuses inside & out. we even changed the battery early on. i spent some time online & asked other mechanics & the consensus has been the bcm. please let me know what you think, i'd appreciate it! dee

ANSWER: Hi Dee,
I am glad that you asked! I would believe that the repair will cost you less than a dollar rather than the price of a replacement bcm. Although you said that you had checked all the fuses I wonder if you looked in the fuse box that is in the cabin, under the dash on the driver side?  I believe that you will find that fuse #12 at the far right end of the row of fuses on the bottom of that 'junction block' is blown. It is 10A size and it powers everything that you described, when it it functioning.
Roland

---------- FOLLOW-UP ----------

QUESTION: i had checked all of the fuses under the dash, but i just went & tried again. fuse looked fine, but put in a new one & nothing's changed. i'm more than willing 2 try anything else! thx, dee

Answer
Hi Dee,
Ok, if the fuse #12 hasn't blown but all the systems that you mentioned still don't work then I believe that power is not getting to the fuse's socket from the ignition switch section that is supposed to do so when you turn the key to the 'run' position. You could use a 12V test light or a voltmeter to see if I am correct about that as the reason for no power getting through.
The only other possibility is that fuse #2 in the power box in the engine compartment which in turn sends power to that section of the ignition switch that powers fuse #12 is blown, so take a look at that one carefully also (that #2 fuse also powers the door locks so that is another way to test for fuse #2 being good).
If #2 is good, but you don't have power at fuse #12 with the switch in the 'run' position then you have a section in the ignition switch that is not conducting. You could try spraying contact cleaner inside the switch through a crack in the body of the switch and if that doesn't fix it then get a new ignition switch.
To get to the switch you have to remove the screws around the parking brake release handle that hold in place the dash lower panel and another screw at the right hand end of that panel which will allow you to drop that panel down. Then disconnect the parking brake cable from the handle if you want to get the panel totally out of the way. Then remove the 3 screws on the under side of the steering column that hold the upper and lower column shrouds that when removed will reveal the ignition switch to be on the left hand side of the column just opposite to the ingnition key cylinder. Try squirting some electrical contact cleaner (available at an electronics store) into the switch to revive the section of the switch that has failed.
Roland
PS Please let me know how this works out, but don't by a bcm in any case because everything points to problem being in electrical supply I described above.. Please 'rate' this answer. Thank you.