Why does the Passat display 'key not found'?
3 Answers
Passat displays 'key not found' due to: 1. Insufficient key battery power; 2. Faulty car sensor. The disassembly method for Passat keys is: 1. Unfold the folding key head; 2. Use a flathead screwdriver to pry the seam in the key slot; 3. Separate the key into two parts - one contains the electronic identification chip with the key head, the other is the battery-powered remote; 4. Pry open the remote's housing with a screwdriver. The Passat is a 4-door, 5-seater sedan under Volkswagen, with body dimensions: length 4933mm, width 1836mm, height 1469mm, and wheelbase 2871mm.
Last time when I was driving my Passat, I also encountered a key malfunction situation and was so anxious that I circled the car for quite a while. This issue is mostly caused by the key battery running out, especially for car keys that haven't had their batteries replaced in three or four years. Another time, I put the key and my phone in the same pants pocket, and the phone signal blocked the key signal. Also, pay attention to the parking location; if parked next to a large transformer or elevator, strong magnetic fields can cause the key signal to be intermittent. By the way, excessive heat from summer sun exposure in the car can also temporarily disrupt the key chip. Finally, check the door sensor module; if the rubber seal ages, water can seep in and cause poor contact. It's advisable to always keep a couple of CR2032 button batteries in the glove box for emergency replacements.
Having repaired Volkswagen cars for over a decade, I know all too well about Passat's key recognition issues. First, try placing your palm against the start button's induction zone - that's the emergency start mode. If that doesn't work, open the key to check the battery compartment; pay close attention to whether the CR2032 battery is installed upside down or correctly. Some owners modify their keys with metal casings - be aware that excessive thickness can block signal transmission. Inspect the RFID sensor near the ignition switch; I've encountered several cases where car wash water seepage caused short circuits. Also, don't forget waterproofing for remote keys - getting soaked on the roof during rain can cause real trouble. If everything appears normal but still doesn't work, there's an 80% chance you'll need to connect to the computer to read fault codes, checking whether the key needs reprogramming or if there's an issue with the door control unit.
