99% chance that a malfunctioning keyless entry remote is due to dead lithium battery. But what if two remote suddenly failed simultaneously, lithium battery reads 3V on voltmeter and the problem not solved after changing a new battery. This make me think of the faulty BCM body control module. After spending 30mins locating and dismantling the BCM, I feel that I should go back to the test the remote unit. On loading two 3V lithium battery ti a superbright led, I found the old and replaced battery drop from 3V to 1.5V. What a shame being fooled by the "normal " looking unloaded battery voltage.