Driver's Door Touch Unlock Sensor
 

My 09 IS250 is no longer unlocking when I touch/ grab the driver's door handle sensor with the key fob in my pocket. It works fine on the passenger side, but not on the driver's door. The lock feature does work when I push the button, but the sensor is not unlocking it. I have to push the button on the key fob to get in.

My brother bought a used handle online and switched it out, but still, the sensor was not unlocking the car.

I guess the replacement handle could've been faulty as well, so now he wants to take off the passenger handle and just plug it into the driver's door to see if it's the handle or something else (since we know the passenger sensor works).

Anyone have any experience with this problem? Could it be just bad luck and we got another bad handle/ touch sensor or something else?

Very good chance it is the door lock actuator.

It relates to the status sensor inside the door lock actuator.
Inside your actuator you have 3 different sensors

• Lock command sensor
• Unlock command sensor
• Status sensor

Your key FOB and electronic button inside your vehicle will send voltage to your actuator no matter what its current status is (locked or unlocked) it will still force the action again.
Your Touch lock however uses smart logic. When you touch the handle it senses if the actuator is locked or unlocked and only sends voltage to the actuator if needed. So if you grab onto the door handle and keep holding it while you have a conversation with a friend it will not keep trying to unlock which would shorten the lifespan of the motor in the actuator.
Without the actuator sending the "locked" status signal the vehicle will think it is unlocked and the Touch handle will not send an unlock request.

Two things typically cause this issue. First is a bad actuator, the status sensor can malfunction inside the actuator.

The second method of failure is due to the installation of the actuator. The problem relates to the circular gear in the bottom corner of the actuator with the cross notches in it. There is a rod with a cross end coming from your door key system that needs to align and fit into this gear on the actuator.

You can test this theory out pretty easy. Unplug the wire harness going to your door lock actuator. The wire harness will have 2 large pins on the top row and 4 small pins on the bottom row. Attach a multimeter to the 2 large pins and set your meter to DC voltage. Now close your door. With the wire harness unplugged the actuator is not sending back the "unlocked" status so your car thinks the door is now locked. Touch your handle and see if you get a +12 or -12v reading.
If you get that voltage reading when you touch the handle it means your car is attempting to unlock door and your old actuator shorted closed, a new actuator will correct the problem. If you do not get any voltage then your problem is further upstream in your vehicle.

Regards,
Actuators Plus

Thanks for the awesome response. We'll try that out and report back with the results.

Because your lock button works (think you said that), the puddle light comes on when the fob is in proximity, yes?
If no, perhaps it is a fob detection issue?

Lock button works and puddle lights do come on, yes.

I had read a thread that said replacing the battery in the fob helped a couple of people so I did that first, but it didn't matter.

We'll test out the actuator as described above. That could explain why the replacement handle still didn't solve the issue.

If you go that deep I would have a replacement actuator available.
JM2C

Good idea. Then I don't have to open up that door more than I need to.

Have you tried replacing your Remote battery?

As I said above that was the first thing I did. Everything works normal on passengers door, just not unlocking on drivers.

Any luck? was it the actuator. Would love to know. Matt

You know we never actually got around to looking into it any further. It wasn't a huge issue and we wanted to fix the exhaust first. Was going to be a winter/ spring project, but then we got stuck home and I've barely driven the car these last 9+ months. Was actually just thinking about it yesterday for the first time in a while. Might be a good time to check it out though since I'm not going anywhere anytime soon. Will update when I do for sure.

Our Actuators dont have proximity sensors or detect anything. It is all done via the handle. I am having the same issue and when i go to the other door handles tho they all work and open the car, except it beeps 5 times and triggers the actuators 5 times.