Infrared keyless entry 95 sl500

[keito]

It seems that my keyless entry is not working. I tried new batteries with no luck. What is the next logical step in this troubleshooting procedure? thanks for the help.

[500SL4Me]

My 1995 did this once randomly as well. Using the regular key to cycle the lock on the drivers door reset it somehow. Not sure it is your problem, worth trying though.

Mine did this only once oddly and normally works fine.

[ulflei]

Probably the vacuum pump

[Lee Wireless]

see PDF

[bayhas]

Originally Posted by ulflei

Probably the vacuum pump

only if the car is flashing green and red, but locks are not operating...

that doesnt sound like it is the case here...



Test the remote itself to make sure it is still operational, hold the button for 3-5 seconds, make sure the tip flashes in red.

next, try to resync the key, lock, unlock the driver door with the key blade, put the key in the ingnition, turn to position 2, then off again, then cycle the key blade one more time in the door, while the green light of the door is still flashing green, aim the remote and push the lock switch. the flashing will pause if the car recieves a signal..

at this point, the key must be resynced, and you should be able to lock and unlock normally with the remote.

if the flashing stops (as mentioned above) but the car still does not recognize the key, you either have the wrong remote, or a bad module.

[Ali Denton-Cardew]

Keito, the electronic internals of key-fob do become damaged or defective over time. High chance that solder joints have become dry, or fatigue fractures developed around a component.
Question - is the keyfob creating an infra-red signal?
Even the visible light 'flash' seen after 2/3 seconds does not always mean an infra-red signal is going out.
Quick way to test this - use any digital camera (or camera-phone). Hold fob pointing toward your phone / camera. Press activation button, watch camera for 'flash' from module that naked eye cannot see. If no 'flash' (which is more like pulses, than a flash) then internals are defective and need re-soldering etc.
Try with any tv or stereo remote to see camera spot what naked eye cannot see.
There is a post of about two years back with photos, where a fob was opened and internals / battery posts re-soldered.

Good luck and regards,
Ali D-C.

[bayhas]

Originally Posted by Ali Denton-Cardew

Keito, the electronic internals of key-fob do become damaged or defective over time. High chance that solder joints have become dry, or fatigue fractures developed around a component.
Question - is the keyfob creating an infra-red signal?
Even the visible light 'flash' seen after 2/3 seconds does not always mean an infra-red signal is going out.
Quick way to test this - use any digital camera (or camera-phone). Hold fob pointing toward your phone / camera. Press activation button, watch camera for 'flash' from module that naked eye cannot see. If no 'flash' (which is more like pulses, than a flash) then internals are defective and need re-soldering etc.
Try with any tv or stereo remote to see camera spot what naked eye cannot see.
There is a post of about two years back with photos, where a fob was opened and internals / battery posts re-soldered.

Good luck and regards,
Ali D-C.

3ali,

the key fob internals consist of surface mount components with a slim to non chance of delaminating under regular to extreme conditions...

also, all components in the key fob are solid state, except for the switch itself.

as far as the infrared beam, it is visible if you look at it in a dark room, so no need for the camera.

furthermore, the PCB, by design, makes it very hard to fail in a fashion that allows the test red LED to be excited, (notice the name "test LED", infrared not to be emmited...

basically the key for circuity is so simple, that you may get all or none in 99.999% of the cases...