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Seeking definitive troubleshooting guide for Door Handle Remote Keyless Entry problem

3351 Views 10 Replies 4 Participants Last post by  hiltonny
Thanks to all prior member posts about the micro switches or the door handle antenna, however, I'm still confused about the troubleshooting steps. There was a detailed matrix posted by one really smart member, but that goes over my head. I'm not that tech savvy.

Is there anyone who can post a step by step procedure to test out the remote keyless entry problem?

My issue is like many others. At first, I noticed that pulling the door handle did not open the door. I can open it with the door key. I put a new battery in the key fob. No change. The 2nd key fob also behaves the same. Strangely, the issue seemed intermittent, but then became permanent.

The passenger door opens without the key. The keyless system seems to work fine on passenger side.

Like probably many unsophisticated readers of this forum, I don't see a definitive "how to" diagnose the Door Antenna Issue vs. Microswitch problems (realizing that there could be other issues also).

If there is someone who can explain the troubleshooting in plain English, it would be greatly appreciated.

Sincerely,

AR
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First, remove the inside door trim, it doesn't need to be completely removed just enough to gain access to the upper rear door area. Separate the black plastic water shield from the upper rear area to gain access to the door handle electrical connector. There's a six pin connector at the upper rear of the door that's held there with a plastic pin through the sheet metal; unplug the connector's two parts. Using an ohmmeter check the pins on the connector half that is connected to the outside door handle.
The YELLOW and WHITE wires go to the outside door handle antenna, connect the ohmmeter to those pins; the reading should be low but not high or shorted, 10-20 ohms is around what to expect. Move the outside handle to the fully open position, the reading should be constant.
Next check the first of two micro switches, connect the ohmmeter to the GRAY and GREEN wire pins. The reading with the outside handle untouched should be infinity, an open contact. Slowly open the outside door handle, the reading should change to near zero ohms, a closed contact. Measure about how far the handle is open when this happens. Continue to open the outside door handle until fully opened, the reading should remain the same, a closed contact. Release the outside handle, the reading should revert back to infinity, an open contact.
Next check the second micro switch, connect the ohmmeter to the ORANGE and BLUE wire pins. With the outside door handle untouched the reading should be infinity, an open contact. Slowly open the outside door handle, the reading should change to near zero ohms, a closed contact. Measure about how far the handle is opened when this happens. Continue to open the outside handle until fully opened, the reading should remain the same, a closed contact. Release the outside handle, the reading should revert back to infinity, an open cointact.
Compare the distance measurments taken if the switches worked, the second switch should close after the first switch as the outside door handle is opened. If either micro switch is bad from the above test you can order a replacement inner door handle or replace the faulty micro switch(s) on the one you have now. I ordered new micro switches using part numbers from an old post (ZD30S20A01), the new switches were similar but slightly larger making them very difficult to install. The old micro switches are potted into the inner door handle so the potting has to be removed with a Dremel or similar tool then the new correct micro switches need to be soldered to the correct wires the old micro switches were connected to. Additional short lenghts of wire need to be added to the old wires if they were shortened in the potting removal. If the handle antenna is bad that needs to be replaced. I did this fix a few weeks ago and found one good micro switch, one bad micro switch and a good antenna. After replacing both micro switches (due to the potting removal it's faster to do both) the door operates like new. There were a few days recently where the door didn't open right but that was caused by a bad contact in the FOB, cleaning the battery contacts corrected it.
The outside door handle has no mechanical connection to the door latch, only the inside door handle connects to the latch with a cable. When the outside door handle antenna recognizes the FOB it then tells the system to allow the micro switch commands. As the outside handle is opened, a molded cam in the handle closes the first micro switch and then the second. Once the system receives this information a motor in the door latch releases the door, that's why there's a short delay when the outside door handle is pulled but not the inside door handle.
In addition to the outside door handle, the door latch has three micro switches, a motor and a lot of parts inside. I switched door latches and the in the door control box from a working car but it was the one bad micro switch in the outside door handle that caused the problem.
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Have you tried another FOB? Poor internal FOB contacts will cause intermittent operation? If an inner door handle microswitch is bad, spraying WD40 won't correct it and neither will rain. If you can't trouble shoot using the above directions can you change the inner door handle or handle antenna? If not then take it to a dealer and be done with it. If you can then start with a new inner door handle assembly but try another FOB first if you haven't already.
The next time the door doesn't open, take the FOB out of your pocket and push the unlock and then the lock buttons to see if the FOB is communicating with the car. If the doors don't lock and unlock the problem isn't the doors it's the FOB. If the doors unlock and lock then the FOB is OK. I had a problem with the FOB where one set of battery contacts was intermittent, the door sometimes wouldn't open and the FOB wouldn't lock or unlock the doors. Inside the FOB one set of battery contacts was stronger than the other set sometimes resulting in no battery power and no door opening.
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