I believe my head could explode at any minute

[Guest Richard D]

Several weeks ago my Reatta began turning on the odometer, lights above the interior door handles, the EL backlight on the console shifter and the climate control backlight. After a new battery problem corrected itself except for the odometer which would only work at random. unless car is in on position. BCM input 106 showed proper level change when lifted, not a major problem. WRONG! Original problem reocurred and I had a dead battery. Tomorrow I will check the input and output of the BCM to verify its the BCM unless someone can wave a magic wand in my direction. Also courtesy don't work from any input such as door switchs, headlight slide switch or key fob which operates door locks and trunk lid.. I am a bit ashamed to admit that I was an electronic engineer im an earlier life. If I were to take it to a Buick, Cadillac and GMC dealer would that be stupid?

PLEASE HELP.

Richard.

zUpdate update UPDATE

When I check both outside door handles the input on the BCM stays at high, before it would stay low until I lift up on the door handle it would switch from low to high. What is common to both door handles? From what I can see is the BCM, I need ideas PLEASE. Rap works fine. Should I call the service writer at the Cadillac, GMC, BUICK dealer? Any chance of them knowing this system?

Edited May 20, 2014 by Richard D (see edit history)

[drtidmore]

Richard,

I know that you are avoiding the pita passenger seat removal and tracing down the gray wires from the door lift handles/BCM, but what you are describing regarding the door lift handles is EXACTLY what you see if there is short to ground ANYWHERE in that circuit. If EITHER door has a short in the lift switch OR in the wiring from the lift switch, the BCM will NEVER switch states on this circuit since BOTH door lift switches are spliced together along with the wire to the BCM (slice of 3 gray wires located under the passenger seat). I had this same problem and traced it to a short in the passenger door lift handle wiring. This is NOT a complicated circuit. Cut the spice open and separate the three gray wires. First, momentarily touch each to ground while having the doors closed (or the door jam switches depressed). When you ground the BCM wire the interior lights will come on assuming a functional BCM. If grounding each wire separately does NOT result in the interior lights coming on, then you either have a short in the wire to the BCM OR a bad BCM. As this is a grounding circuit, no danger in grounding each wire until you find the BCM wire. Label it BCM and THEN using an ohmmeter check each remaining wire separately for continuity. If either remaining wire indicates continuity to ground, that is the side with the shorted door lift switch wiring OR a stuck lift switch.

You are NOT going to be able to troubleshoot this from the BCM codes. FYI, assuming a short in the door handle lift switch circuit, the key fob will NOT illuminate the interior lights until that issue is resolved. However, the issue with the turning on the courtesy lights from the headlight switch or opening a door is a separate issue from the door handle lift switch circuit.

[Guest Richard D]

Thank you David, you have read me correctly, I have not pulled either seat yet..I have a back injury that occurred in 1975 when I was working at WMYQ 96.3 FM which was an amazing job to have at 17 to 21 years old. I lived in South Miami and the station was on Miami Beach, about a 75 mile round trip. I had a 100% stock 1973 Camaro LT with the Chevy sb 350, 4bbl auto turbo 400 and at 2 dollars a shot maximum fuel purchase I began towing my boat to the marina where I could fill the 18 gallon tank, drive it home and siphon the fuel into the Camaro. This became a hassle so of course I bought a new Honda cb 350 and this worked great, for about 8 weeks when a nice lady ran a ted light and I had a close encounter with her rear door. Back injury and broken wrist. This is why I had a hard time removing seat. My mechanic offered to remove it and reinstall for free. That will be the next step, maybe I can fix his sound sysrem or TV.

Gray wire on passenger side mostly could be on drivers side as well but start on pass side first.

THANKS TO ALL FOR YOUR HELP AND ADVICE

Richard.