To determine if a vehicle's keyless entry system is functioning correctly and identify any issues with key fobs or proximity sensors, here are some steps and questions to consider:

Inspection Steps:
Check Key Fob Battery:

Ensure the key fob battery is not dead. Replace the battery if necessary and see if this resolves any issues.
Test Range and Responsiveness:

Test the keyless entry system from various distances. Ensure the Car Door Locks and unlocks reliably within the specified range.
Observe if there are any delays or unresponsiveness when using the key fob.
Proximity Sensor Test:

Approach the vehicle with the key fob to test the proximity sensor. The vehicle should unlock automatically or respond when the door handle is touched (if it has this feature).
Verify if the proximity sensor works consistently from all angles and distances.

Spare Key Fob:

If available, test the system with a spare key fob to determine if the issue is with the primary fob or the vehicle's system.
Inspect Key Fob Condition:

Check the key fob for any physical damage, such as cracked casing or water exposure, which could affect its functionality.
Software/Firmware Updates:

Verify if there are any available software or firmware updates for the vehicle's keyless entry system that need to be installed.
Diagnostic Questions:
Consistency of Issues:

Do the issues occur consistently, or are they intermittent?
Is there a specific pattern or scenario where the keyless entry system fails to work?
Range Limitations:

Have you noticed a reduction in the effective range of the key fob?
Does the keyless entry system work better at closer distances but fail at longer ranges?
Proximity Sensor Problems:

Are there any specific spots around the vehicle where the proximity sensor fails to detect the key fob?
Does the vehicle fail to unlock when you are standing next to it with the key fob?
Environmental Interference:

Are there any environmental factors, such as electronic interference or physical obstructions, that could be affecting the keyless entry system?
Have you noticed the system working better in certain locations or conditions?
Vehicle Battery Health:

Is the vehicle's battery in good condition, or could a weak battery be affecting the keyless entry system's performance?
Service History:

Has the keyless entry system been serviced or repaired previously?
Are there any known issues or recalls related to the keyless entry system for this vehicle model?
By conducting these tests and asking these diagnostic questions, you can identify the specific issues with the keyless entry system and determine whether the problem lies with the key fob, the proximity sensors, or the vehicle's electronics. If the issues persist, it may be necessary to consult a professional automotive technician for further diagnosis and repair.