We received a Volkswagen Jetta 2010 model for which all the keys were lost. We made the key, programmed the remote and everything seemed to be fine. After, 2 hours, Remote stopped working suddenly. Customer was able to start the car but remote was not working. We rematched the remote and got confirmation from the device that remote matched successfully but still it was not operational.
We thought that lock might be faulty, as when we take out the key from ignition it sends a signal (which is interpreted as No Key in lock by car’s computer) and might not be passing through. We removed the lock so that car doesn’t detect any key at all but all in vain. We cleared all faults, checked all fuses, nothing worked. When we were about loose hope, remote suddenly started working. As we have done nothing accountable which could have made it work, we thought of waiting little more and see whether it stops working or not.
After 3 hours, remote again stopped working. On further investigation we found that there is a unit attached to ignition lock below steering wheel which was faulty (Pictures attached). We opened that unit and found traces of water marks. Someone might have cleaned the steering wheel with some water based spray which seeped into that unit and causing trouble. We cleaned the marks of water and now remote is working fine.