When I lock the car,98 C5, using the key FOB, after a minute or two, it unlocks! bought another FOB, same thing, reprogramed both , same thing!, so I don't use them,
Why?? read service manual serveal times, did exactly as it says
( about reprograming FOB) anyone hava any ideas? My luck it'll be the module ( same one for the TPS) I'll bet!
and yes ,I'm have a time with the TPS too, can't get one tire to program, bought new sensors, same thing, all leads me to believe it the module.
gee this is fun! but I love the car!!!!!

Thanks
cruzn57

 

is your car a 99 or earlier? Does your key fob have an on and off switch on the bottom?

VR

 

its a 98 , with passive switch,
thanks

 

Is tha passive switch on?

More wierd with my '98 is just about every morning when I start, the doors will lock. Outside the garage will not do this...wierd?

 

I have had the passive switch off,
on both FOBs, should they be on?
I'm so confused ! ( nuthin new for me!)

 

Those switches get funky . Had the same problem. Had to slide them back and forth a few times to clean the contacts and it's fine now.
Good Luck!

 

so ...........??
if I set the keys on the roof, and wait, after a few minutes, click, it unlocks,
anybody any ideas?

 

Set the passive switch to the off position and it will stop doing this. With it turned on, even a small amount of motion will cause the FOB to start transmitting and as long as you are near your car it will unlock your doors. I believe the '97-'99's were the only year models to have the passive "on-off" switch on the FOB. HTH

 

I'll try that .see what it does.
again thanks

 

yup

 

Look in the OPTIONS page on the DIC program buttons on the right side of your dash. There should be a passive feature ON/OFF setting. Make sure that it is O F F !!!

There are a couple of other things that will cause the TPS and FOBs to whack out!

One issue is battery voltage. How old is your battery and what condition is it in? If the battery voltage is going low at start up, the FOB will loose sync. Look at thre DTC codes that are stored in the DIC. See if there are any RFA related codes or any U1000 series codes.

The other problem that can effect the FOB's and TPS is this chassis ground.\






You will have to pull up the plastic sorround and lift the mounting tab off the stud. Disconnect the battery, remove the nut, clean the eyelets and the chassis metal mounting area where the eyelets contacts the chassis. While you have the battery terminals off, clean them with a wire brush, spray the terminal out with brake parts cleaner and then WD-40. After they are clean, torque the terminal bolts to 11 ft/lbs.

See if that makes a difference. Let me know how everything turns out.

BC

 

I have a 6 mo old red top optima, voltage is 12.8 car off, and 13.9 running, I'll check the ground wire, (never even thought of that)
and.......... I'll run the DIC for passive OFF, (I'll bet thats it, as I have gone somewhat overboard on that end) ( meaning I had to walk away or do something regretful)

A BIG thanks!!!!!!!

 

Great info Bill C.