Key Fob Not Working

[SoccerDadrx]

So my 2007 rx350 was sold to me with only one key. Never had any issues with the fob, but suddenly stopped working. Red light was still coming on, but replaced the battery anyways. Still didnt work. Is there a fuse associated with the receiver in the car I should be looking at? I didnt see anything obvious on the fuse panel chart. I am ordering some new keys from 1010keys on ebay, so I will find out if the key stopped transmitting the signal.

Just side notes: electric mirrors work, and the cigarette lighter works as well, those were commonly associated on some other lexus model forums, with a blown fuse.

The car starts with the key as normal, and unlocks the doors, but none of the three buttons work. Thanks for the help!

[RX400h]

On 12/4/2024 at 4:27 PM, SoccerDadrx said:

So my 2007 rx350 was sold to me with only one key. Never had any issues with the fob, but suddenly stopped working. Red light was still coming on, but replaced the battery anyways. Still didnt work. Is there a fuse associated with the receiver in the car I should be looking at? I didnt see anything obvious on the fuse panel chart. I am ordering some new keys from 1010keys on ebay, so I will find out if the key stopped transmitting the signal.

Just side notes: electric mirrors work, and the cigarette lighter works as well, those were commonly associated on some other lexus model forums, with a blown fuse.

The car starts with the key as normal, and unlocks the doors, but none of the three buttons work. Thanks for the help!

CoPilot response:

Quote

It sounds like you've done a good job troubleshooting so far! Since the electric mirrors and cigarette lighter are working, it's unlikely to be a blown fuse affecting those components. However, there might still be a fuse related to the receiver for the key fob.

For the 2007 Lexus RX350, the relevant fuse is likely in the engine compartment fuse box or the passenger compartment fuse box. Here are the steps to check:

1. Locate the Fuse Boxes: The engine compartment fuse box is usually under the hood, and the passenger compartment fuse box is typically under the dashboard on the driver's side.

2. Check the Fuse Diagram: Refer to the fuse diagram in your owner's manual or look up the fuse layout online. Look for a fuse labeled something like "MPX-B" or "Security System" which might be related to the keyless entry system.

3. Inspect and Replace: If you find a blown fuse, replace it with one of the same amperage rating.

Since you're ordering new keys, it's a good idea to check the receiver and connections as well. If the new keys still don't work, there might be an issue with the receiver or the car's electrical system. Also note that some Costco stores have a keyfob replacement service that includes required programming.

 

[SoccerDadrx]

22 hours ago, RX400h said:

CoPilot response:

 

Well, I just pulled all the fuses from the interior panel. None looked bad. Tried the fob again, and it works. Not sure if I reset the system, but at least the old key is working.