Maybe someone can help me find the problem to my Keyless entry problems.

Front Driver and passenger door handles have touch sensitivity features that allows you to lock and unlock your car. It also has a sensor that senses your proximity when close to the car and turns on the paddle lights on your mirror and inside the car as you get closer.

I think this sensor when bad on my Driver side.

The issue I am having is;
my driver side does not sense me at all.
when I pass by the driver side, the light does not turn on.
Also the front driver handle does not lock or unlock.
the passenger side however, works properly.

the remote works good and turning the car on works fine.

I have checked for Fuses, and all are fine.
The sensors on the door handle works good. (Tested by removing door handle and testing in other Lexus)
The keyless entry antenna located in the spare tire zone in the trunk, works great as well. (Tested with another car)
And the receiver Assy located in the driver upper quarter panel works good too. (Tested with another vehicle)

Am I missing any other sensors? Proximity sensors etc?
BSM works as expected so it would not be the proximity sensor for BSM located on the right and left side of the rear bumper.


This problems happens after getting my car back for the bodyshop. Car was with a dead battery for a few months and had to be jumped in a few occasions. Everything has been plugged in properly. Checked myself. And all fuses are in good condition.


Please help.


Thanks in advance.

 

The issues you describe with the driver's door suggest that the vehicle is not seeing the key...that's why nothing is working.
At first glance it would appear the issue was the door handle, as that holds the antenna for sensing the key...but you stated you tried it on another Lexus and the handle works fine.
If you're absolutely sure the handle works ok on another car, then the only thing left is the circuit for the handle...or the connection right at the handle.
Below is a diagram of the two wires that feed the antenna circuit...basically you need to make sure both the wires are fine. The Certification ECU is on the passenger side behind the glove box on the right side.
What was it in the body shop for?

 

Hello Sasnuke, thank you very much for always coming to the rescue.

Correct, my car does not sense the key on the left side only. The driver side does work good.
Thats why I was trying to troubleshoot around tracing the handle, antennas and modules. All in which appear fine. The bodyshop where my car was tested the handle in another car and I tested it by connecting it on the other side (passenger) and worked fine.
So since you are staying there is no proximity sensors detecting the key and it is the handle that senses this, then as you said, it’ll be the two wires. I have to see what kind of signal I am to spect to check and see if it is proper. Next would be the Certification ECU.

This is going to be harder than I though 😫


Car was at the shop getting painted. They took the handles and doors off and then put back on. They can’t find a way to fix it. So it’s left up to me

 

Given the new info about what the body shop did to the vehicle, I highly (I mean highly) doubt there is an issue with the Certification ECU.
Since, by your account, the Smart Access and Push Button Start for the rest of the vehicle works perfectly fine, then I really doubt this one circuit within the Certification ECU for the drivers door has failed.
If I was a betting man, I would say it's one of the two wires...G (Green) or B (Black) between the ECU and handle.
If they took the door off the car, that means they either removed the wires harness inside the door (which I doubt), or they removed the harness from inside the lower A pillar and pulled it through when they took the door off.
It could be as simple as connector NQ1 is not properly plugged in. Have you noticed anything else not working? Drivers window? Power side mirrors? etc.

If it was me, I would disconnect the handle and disconnect connector C at the Certification ECU and then check the continuity (resistance) of either of the two wires.
Ideally you would be looking for less than 1 ohm each wire, preferably 0.3-0.4 Ohms each. If one of the wires has high resistance (over 1 ohm) or no resistance, then that is the wire with the issue.
I'll post a few more pics to help you out today when I get a moment.
Before I do the step I just mentioned, I would probably find NQ1 and see if it's plugged in ok and all the pins are fine. I think this is going to be an easy fix once the issue is found...which is going to be the hard part.

 

I suspected this as well. And when I was testing the handle on the other side I made sure the conections were good. Both at the handle and the door. All the door functions were as expected except the door handle. But the sensor on the door handle works on the other side. So yeah let me test for a signal through the wires feeding the handle and see what we get. Can you send me a DM on Instagram? @3ISFSPORT

once again thank you

 

I don't have Insta...I know, what am I, a cave man lol
Also can't post pics on the DM's of the forum...for some reason in the DM's they need a URL link for the pic..really?!?!
I'll post the pics here, and then just DM me with any questions or if you need more info, etc.
Will be grabbing some pics to post shortly.

 

Given the location of NQ1, it would have been ideal to disconnect if the door needed to be removed. The colors of the harness are just for reference in the pic, on the car the harness casing are all black...except for the airbag harnesses, which are yellow.
The purple part labelled "N" in the pic is the harness outside the A pillar where is then goes into the door...hence why NQ1 would have been ideal to disconnect.
My first check would be to disconnect NQ1 and the door handle...then check continuity of the Green wire (NQ1 pin 31 (see second pic below) to the door handle connector pin 6)
Then I would check NQ1 pin 32, the black wire, to the door handle connector pin 4.
Both should be below 1 ohm, and ideally 0.3 - 0.4 ohms. If there is no continuity, then the wire is broken, if the resistance is over 1 ohm, then something is wrong with the wire, like corrosion or it's being pinched to body ground.
Chances are, if anything, the wire is broken...the Green or the Black, or both.

NQ1 location

NQ1 pins - G for Green, B for Black

 

Here is the location of KQ1...easy to access and check to make sure everything is plugged in properly and not damaged.
Given the location of NQ1 and KQ1, I can't imagine the issue with either wire is beyond KQ1 towards to Certification ECU, as the ECU is on the other side of the car.

KQ1 location

 

Also, the pins are super small on these connectors...so likely the head of the lead on your multi-meter is probably way too big.
Consider using a pin (like a sewing pin) or a paperclip in conjunction with the multi-meter lead.

 

No instagram, what the... lol

Thank you for being super detailed about this. Makes complete sense on trying to find the problem at the handle connector down to NQ1 or possibly KQ1. Ill work on this tomorrow and see what my findings are. Wish me luck lol