Key Remote Cannot Lock-unlock Car

[rtd111]

91 LS400, 155K miles

Q: How can I diagnose problem with my keyless remote? It fails to lock-unlock the doors or arm/disarm the alarm.

Details...

I got this car used from a dealer almost 10 years ago. From day one the remote on the key could not arm/disarm the security or lock/unlock the doors. As "discussed" during the purchase, I did take the car in to have this issue looked at. In fact, had to take it several times, and in the end the svc dept said they will not be able to make it work and I would have to just have to live with it. I know I got taken on this one.

Why am I bringing this up now? Well, I happened to read a post on this forum about reprogramming keys and ECU (though it seems the codes are in a transponder chip not related to the ECU, if that's true of 1st gen LS400s as well). I now would like to consider all options to make this work. Its likely that something component (transponder, ECU, ???) was switched out in this car that's caused the keyless lock/unlock to fail.

Not having the remote work has always been a pain. Furthermore, over the past several months, the key will not insert into the driver side door lock and is barely working on the passenger side door. (Yes, I have tried WD40 and some others, though not a graphite lubricant yet). At some pt, I will need to fix the pins and springs or whatever it is that's messed it with the mechanism up but I fear I wont be able to unlock the car one day. The spare key (without the keyless remote) works a little better/smoother on the passenger side door, and occasionally (1 in 5 times) will even unlock the driver side door.

BTW, no problem with the ignition and starting, etc with either key.

Thoughts?

Thanx in advance for your responses.

[streski58]

You may have the wrong remote. Many of the Lexus remotes look the same, but the electronics are different. here are some instructions on how to program the remote into the car. If that doesn't work, you may want to purchase a new remote head key for your car & try to program it. Check out the the following website if you need more help. http://www.sparecarekeys.com

1. Remove the key from the ignition switch. Open the driver’s door. Make sure that all other doors are closed.

2. Insert the key into the ignition switch, then remove it.

3. Press the LOCK and UNLOCK on the vehicles door lock control switch at one second intervals five times.

4. Close and re-open the drivers door

5. Press the LOCK and UNLOCK on the vehicles door lock control switch at one second intervals five times.

6. Insert the key into the ignition switch.

7. Switch the ignition ON and OFF once to program a key remote transmitter code, while retaining the original codes.

8. Remove the key from the ignition switch. System should now lock and unlock the vehicle once. System will then lock and unlock the vehicle one to four times slowly to indicate the number of key remote transmitters registered.

9. Press and release LOCK and UNLOCK buttons together.

10. Press any key remote transmitter button for a minimum of one second. System should now lock and unlock the vehicle once to confirm registration, twice will indicate registration has failed.

11. If required, repeat button procedure to program remaining key remote transmitters.

12. To exit programming mode, Close driver door, or insert the key into the ignition.

***NOTE: A maximum of 4 remote transmitters can be programmed.

[rtd111]

Thanx for the instructions.

I have not tried this yet -- can't wait to go out and do this, hopefully in the next 20 mins. There is a question however:

9. Press and release LOCK and UNLOCK buttons together.

Which LOCK and UNLOCK buttons. On the door, its a toggle. On my key, its the old style with a single button on the side of the key. Its not a dongle with lock, unlock, alarm,... buttons.

And

7. Switch the ignition ON and OFF once to program a key remote transmitter code, while retaining the original codes.

Who's retaining the orig codes: key or the car ("System"?

Appreciate it.

[rtd111]

Well, here it is.

In any case, these procedures did not work for me. (The battery in the key reads 2.94V)

In the link above, step 8 fails: when I remove the key, the locks do not cycle.

Maybe I am imagining it, but its gotten difficult to insert this key in the ignition since I tried this (about 10 times). My earlier fear that the problem with the key not working on the driver-side door creeping to the ignition :(! During reprogramming, I had to abort a couple of times because the key would not sink all the way in. Even when it did, I had to wiggle, remove, rotate 180deg & reinsert, wiggle, and maybe it would sink. Its getting a little edgy. I am going to stash this key away.

Because the other key, which does not have the keyless entry remote, works quite smoothly on the driver's side door as well as the ignition. I dont have to wiggle it or anything to make it work. Its the one I will begin using here on out.

Its subtle but I think the "teeth" on the two keys don't quite match.

Any other ideas or suggestions. Perhaps I should call Lexus and get the one time lifetime replacement of the ECU and get new keys reprogrammed?

Grazie.

[streski58]

Well, here it is.

In any case, these procedures did not work for me. (The battery in the key reads 2.94V)

In the link above, step 8 fails: when I remove the key, the locks do not cycle.

Maybe I am imagining it, but its gotten difficult to insert this key in the ignition since I tried this (about 10 times). My earlier fear that the problem with the key not working on the driver-side door creeping to the ignition :(! During reprogramming, I had to abort a couple of times because the key would not sink all the way in. Even when it did, I had to wiggle, remove, rotate 180deg & reinsert, wiggle, and maybe it would sink. Its getting a little edgy. I am going to stash this key away.

Because the other key, which does not have the keyless entry remote, works quite smoothly on the driver's side door as well as the ignition. I dont have to wiggle it or anything to make it work. Its the one I will begin using here on out.

Its subtle but I think the "teeth" on the two keys don't quite match.

Any other ideas or suggestions. Perhaps I should call Lexus and get the one time lifetime replacement of the ECU and get new keys reprogrammed?

Grazie.

Sorry, when I read your post, I missed that it was a 91. On this model replacement remotes must be purchased together with a control module ROM chip from the dealer. If your battery is good and still isn't working, you will need to replace both of your remotes. You will have to purchase them through Lexus. You can still purchase an extra non remote head key at http://www.sparecarkeys.com

[glenmore]

91 LS400, 155K miles

Furthermore, over the past several months, the key will not insert into the driver side door lock and is barely working on the passenger side door. (Yes, I have tried WD40 and some others, though not a graphite lubricant yet). At some pt, I will need to fix the pins and springs or whatever it is that's messed it with the mechanism up but I fear I wont be able to unlock the car one day. The spare key (without the keyless remote) works a little better/smoother on the passenger side door, and occasionally (1 in 5 times) will even unlock the driver side door.

BTW, no problem with the ignition and starting, etc with either key.

Thoughts?

Thanx in advance for your responses.

The lock difficulty sounds exactly like my situation. On mine, the key with the button remote is just too worn. Compared to a relatively fresh key, I could see the wear points. It was getting had to unlock both doors and I could not get into the trunk at all. My second key, valet key and wallet key work fine.

glenmore

1990 LS400 (152K)

1991 300CE

2000 C280

[streski58]

If I were you, I think that I would order new keys cut to the manufacturer VIN number. That way all of the cuts will be to the factory specifications. The two keys cost $99.00 from sparecarkeys.com. It would be worth a try & if it works, definetily a lot less expensive than taking your locks out & having new wafers put in them.

[rtd111]

I called the local Lexus dealer. Here's the scoop.

To have the convenience of the remote key, I'd have to order "a chip" and one (or more) remote key(s) programmed for that chip. The cost is $425. He looked up the record on the car and said he is not sure of the "computer" is bad as well. He can find out only after getting the chip and the matching key. I did not ask him the implication if the computer was bad.

Question: has anyone done this before? Or any other sources for the "chip and key" combo?

I also could get a regular key, ala sparekeys.com, and that would be $75 for one.

Many thanx.

[ylekiot1]

I had this issue with the locks not working on the car (1990). It turned out that the frequency module (in the receiver module in the trunk ) that matches the key electronics was loose. It worked after reseating the module in the receiver unit. It is to the right of the antenna assembly in the trunk.

I did this first to make sure the key works. The shop manual says to turn the radio to a low fm station (I don't remember the specific frequency). 88-92? Get the car in a location where it does not get any low frequency stations that might interfere with the car key. Go through the frequencies one by one and then push the button on the key. You will hear some interference (it is slight). If that works for you the key works. Then move to looking at the module in the trunk. I have the shop manual and can give you some pointers if you like. I just sent you a pm with my contact info.

[SKperformance]

Skip all the pain and buy a new alarm with a car starter and have more feature all in one for much cheaper.

Also using pb blaster will work in the lock much better than wd 40 ever could.

[Hannah06]

Remote door locks that do not have to worry anymore. And do not worry about losing the key. Just enter the key code and the door opens. One of the best advantages is that you can enter the repair man to come home when you're away. They come home, what they need and leave. For the code, and can be copied down, when you do not have.

auto locksmith Arvada

[billydpowell]

Remote door locks that do not have to worry anymore. And do not worry about losing the key. Just enter the key code and the door opens. One of the best advantages is that you can enter the repair man to come home when you're away. They come home, what they need and leave. For the code, and can be copied down, when you do not have.

auto locksmith Arvada

what are you trying to tell us??? I don't understand, please explain..