2002 Lexus IS300 - Locking System Problem

"... I was a dummy (this hasn't changed) and opened the drivers side door while it was raining very hard." Would it have been a smarter move to stand in the rain and wait for it to subside? I doubt the rain incident has anything to do with this. I also doubt that an actuator is the true culprit.

To recap, please confirm:
1) The remote UNLOCK feature no longer works, but the remote LOCK function does still work.
2) The driver's door UNLOCK switch no longer works UNLESS the ignition is turned on, but the LOCK function does still work all the time.

This CA 501; did you install yourself? From your description it sounds more like one of the varied connections is loose.

Very interesting! It appears to be a resistive joint/connection on the wiring harness running inside of door frame. A drop of water on any of the plug/socket could be the culprit.

"To recap, please confirm: 1) The remote UNLOCK feature no longer works, but the remote LOCK function does still work.

2) The driver's door UNLOCK switch no longer works UNLESS the ignition is turned on, but the LOCK function does still work all the time."

1) Correct. Actually, to add to the confusion (or maybe this will clarify) - I have to press unlock on my remote before I remote start the car or else the alarm will sound. So unlock on the remote is doing something. (And I never had to do this before.)

2) Correct, both the driver's door and passenger's door unlock switches do not work while the car is off, but will when ignition = ON. They will also work if the ignition is turned on, then back off. If I lock it again though it will stop working.

The single previous owner of the car installed it himself. He did that work professionally but that doesn't mean something couldn't be wrong. So your suggestion would be to check all connections? Should I look at all fuses, too? Should I check connections inside of the door as Joshi suggests, too?

Yes, I suspect a faulty connection. Probably has corroded over time, and may well be one of them inside the door as suggested by Joshi. Neither Doorman's Chick nor I can see it from Fargo.

I suspect there is a sensor wire reading open, and when the ignition is on, the car logic controller overrides this signal and then things function as they should. Question: If the ignition is on, does the wireless remote UNLOCK function as it should? If yes, this is a good indication there is a loose connection.

[edit] "I have to press unlock on my remote before I remote start the car or else the alarm will sound." This sounds odd... was that the required sequence prior to this trouble? Remote start will (all I have seen, anyway) not start unless the doors are locked; as I consider, I believe the controller will lock the doors (if unlocked) before starting.

"Question: If the ignition is on, does the wireless remote UNLOCK function as it should? If yes, this is a good indication there is a loose connection."

Good question, I just went out to the parking lot to try this. Put the key in the ON position, and NO the wireless remote unlock does not function! Again I hear the "CLICKclick, CLICKclick" and the lights flash twice. It knows it's supposed to be unlocking, but it isn't.

What is this an indication of?

It's an indication that the remote control system is functioning (that's the clicking you hear) but the relay output is not reaching the wire that operates the unlocking solenoid.

You need to find where and how the CodeMaster was installed in the vehicles wiring, depending on the installer you'll find he used a proprietary connector that installed between two factory connectors (better) or a wiring harness that involved splicing into the factory harness (worse).

Once you find the connection method make sure everything is tightly soldered (ideal), connected using squeeze on connectors (they can loosen over time), or the factory harness was cut and the wires connected using crimps or wire nuts (worse). If all that checks ok then check for a loose or corroded ground wire that prevents the signal from the relay contact from completing the circuit.

A simple continuity checker will make this process a lot easier.

You are narrowing things down.

1) If the actuator works with the ignition on, it is not bad. Do not buy one.

If the unlock system should work with the key off, but does not. AND the unlock system works with the key on, It appears that you are lacking power to a repay in the off position, or that relay is not passing power in the non activated position which it would be in if the ignition was in the off position. If you hear relays clicking with the remote, but nothing unlock, it sounds to me like a relay is activating on command, but not switching the power as needed.

Check for any fuses that may have failed. Not just blown fuses, but also corroded connections on the fuses themselves. The fuses for the remote should be in-line fuses, and not in a factory fuse box. The fuse box is usually a good place to start the search for the fuses though.

If that search does not yield any problems, your next place to look is at the relays that you hear clicking. There are only a few common relay configurations, but the most common one has the terminal marked (30) as power to the relay, (87A) as normally closed, (87) as normally open , (85 and 86) as the activating coil.

Look carefully with a test light or meter, and this should get you your answer as to what has failed. Good luck.

Remote lock/unlock uses a solenoid and a wire link to manually engage/disengage the door lock mechanism. That's the solenoid making the clicking noise you here. Since the RF transmit/receive system and the solenoid are working I would suspect that the problem is mechanical which will require removal of the door panel to troubleshoot and repair.

"... I would suspect that the problem is mechanical..." I doubt that. It is reported that the entire system works correctly and consistently when the ignition is in the run position, thus making mechanical trouble unlikely. Symptoms indicate a logic output trouble; whether it is the controller itself or the controller is confused by a now improper input is the gremlin to be discovered.

Regarding the remote unlock not functioning when the ignition is in the run position, I have no answer as to a specific probable trouble. With the symptoms described so far, it doesn't sound like the ground wire but I would check them all anyway. It is also possible the controller itself has sprung a leak.

[edit] yamdankee, do you still have both of the remotes? Do both exhibit the same symptom? Possible trouble source, but I sort of doubt that as well.

This could also be a computer problem.

a little wd-40 and a hair dryer might fix the problem. you'll need to take the door panel off.