Keyless Remote Intermittent

**79Firebird_99TA** · 11-02-2011, 07:14 AM

It works maybe 10% of the time. Getting tired of setting alarm off ....

I have replaced the battery, remote as well as reprogrammed ..... and this past weekend I took out the bcm and resoldered suspect cold solder joints.... to no avail. I also checked all diodes, transistors and electrolytic caps. Oh and on the programming, when I get to the part of holding down the lock/unlock buttons ... I never get the confirmation pulses to the door/trunk pulses... which is really no surprise as something is not receiving the signal.

Don't have a service manual so here are my questions: Where is the receiver ... in the bcm, through the radio antenna? Maybe I missed something in the bcm and just need to buy another one. Sure would be nice to swap with known good one for test.

Any help would be appreciated.

**cammed goat** · 11-02-2011, 02:55 PM

I might be wrong, but I think the receiver is in the center of the dash. You either have a bad BCM, bad ground or a bad sensor in either the hood, doors or trunk areas.

**79Firebird_99TA** · 11-02-2011, 06:40 PM

Well I found and bought one for 55.00 shipped from ebay. We'll see what we see.

**cammed goat** · 11-02-2011, 06:45 PM

OK. Let us know what happens.

**79Firebird_99TA** · 11-08-2011, 12:04 PM

Installed the bcm but now have the security light and no crank condition. I'm sure it's the vats system. Is it possible to decode that resistance it's looking for by serial number on the unit? My other option was to wire in a 15k multi-turn pot and try each of the 15 resistances that we have for our cars.

**79Firebird_99TA** · 11-08-2011, 12:33 PM

Just in case ... the serial number is *87UPL01A10267287* ....at least I think this is the serial number. Other numbers on the device are:
GM 09353691 CANADA 218 101 440A
MODEL/FCC ID ABO1702R UPL

**79Firebird_99TA** · 11-09-2011, 08:14 AM

I just stepped through each and every resistance and couldn't clear the security light. should I be removing power from the bcm every time that I try a new resistance to reset it or something? What am I missing here? Can someone help?

Thanks

**79Firebird_99TA** · 11-09-2011, 09:11 AM

FYI - the antenna is in the BCM.

**cammed goat** · 11-09-2011, 06:41 PM

Is the BCM used or new? I think a new BCM has to be programmed. I don't know about a used one. Unless you have a Tech2 scanner and do a case relearn to clear the BCM and then reprogram it to the car.

**79Firebird_99TA** · 11-10-2011, 07:43 AM

Thanks for the reply. cammed goat. The BCM is used. I was able to get the resistance from the previous owner - which was 3kohms. It still did not work until after I disconnected battery for 10 minutes. So that information is stored somewhere else. That's the good news ... the bad is that I still have the original problem as the remote entry still isn't working. Sigh .....

**79Firebird_99TA** · 11-10-2011, 07:55 AM

At this point, I am going to assume that both BCMs are good and that they are receiving the remote's wireless signal. I have a new remote as well. After installing the 2nd bcm, I did attempt to reprogram each remote and the system does go into program mode. I never get the pulses to the door locks and trunk after holding down lock and unlock buttons.

So from the bcm to the load it's like there's an "air gap". Does anyone know the signal passes through a relay or the main computer? Maybe it's time for me to buy a service manual.

**79Firebird_99TA** · 02-04-2012, 08:30 PM

Well I did program things so that the alarm will not set unless the car is locked from the wireless. So I have been using the switch to lock and key to unlock. On a whim I decided to buy another transmitter with the same exact part # and FCC ID..... viola .... it programmed the first time (with the replacement BCM). But then it turns out that it's still intermittent. I just got home and it wasn't working so I tried to reprogram it - NG. It did however relink by pressing the lock and unlock buttons for 8 seconds. We'll see if it hangs in there.

**cammed goat** · 02-05-2012, 08:54 AM

I am wondering if there is a ground fault somewhere. Maybe caused by vibration or something.

**79Firebird_99TA** · 02-06-2012, 03:03 PM

I had wondered that as well. I touched up solder joints in the original BCM to no avail.... and then the same behavior with the replacement BCM. I will say this ... now I've noticed that for the last 2 days, if my remote doesn't work I can hold the lock/unlock buttons to relink and it works for a while.

Also ... I had another non-programmed new remote sitting in my console. I removed it and haven't had any problems for the past day. Maybe RF interference? Time will tell ..... I will post back.

**79Firebird_99TA** · 02-12-2012, 01:14 PM

So it's been roughly a week since I posted. The 2nd remote continued to be intermittent. So I programmed a 3rd remote that I purchased that had the exact FCCID and part #. It works flawlessly!!

Moral to the story .... if the problem is the remote, do not buy one that is not an exact replacement. Make sure that the FCCID and part number are exactly the same as the original.