foos

Hi bought this car a few months age for my wife to drive to work. Has run really well till last week. Car will start but shuts off after 3-5 sec. I borrowed a scanner from auto zone but it gave me a pass, no codes found (which is strange since it's had a check engine light on since we got it). I had to have it towed to a local shop for diagnosis. They are saying the immobilizer control module is bad and has to be replaced to the tune of 900.00 for the part and install/program. He also said there may be more problems but they wouldn't be able to say until they replaced this part. I went ahead and paid for the tow and diagnosos and got my keys. Left the car there until I could figure out how I wanted to proceed. I called the closest lexus (dealer 45 miles from me) and they said if it was the immobilizer it wouldn't start at all. So I have a few questions maybe one of you experts can answer for me.
1. Can the immobilizer unit be permanently bypassed somehow?
2. Can a used module (from junkyard) be programmed for my car?
3. Is there a chance the shop that installed the alarm/remote start messed the immobilizer system up? After the alarm install the electric locks don't work with key, remote, or button. you have to manually lock each door.
4. If I have to purchase the part I would like to at least install it myself, is that doable or would special equipment be needed to program?
5. If this was your car how would you proceed from this point?

Thanks

uuuuu

You have an aftermarket immobilizer unit / remote start?

foos

the guy we purchased it from had an alarm systen with remote start installed just before we got it. not sure if that means they put in a aftermarket immobilizer unit or just programed the stock one? was just curious if a bad alarm install could be related to the problem considering the locks not working and it being really hard to activate alarm or remote start. Have to hold remote next to car and push button over and over for a few minutes.

foos

hmm...not getting the responses I had hoped for. I'm sure being a Lexus noob as well as a forum noob doesn't help my chances much. Just don't have anywhere else to turn as I have a very limited wallet. I realize now, it was not a smart move to buy a Lexus. My wife's minivan was totaled from a hail storm, after the insurance company beating we took I had limited funds to get my wife a car for her new job. She fell in love with this Lexus and after researching I found the LS 400 to be a very reliable car. I got the car for 3600. which I thought was a good deal even though it had 170k. Other than a little cosmetic (mostly paint) damage it's in very good shape. Interior is almost perfect and was running very smooth and strong. I figured I could do most of the maintenance myself and it would last at least a year or so until I could afford a newer car. What I failed to acknowledge is if anything goes wrong, even something small like the immobilizer, it would be very hard to diagnoses and very expensive to repair. I can't say I wasn't warned, but I really wanted her to have a nice car to drive. After years 15 years of staying home, raising 5 kids, and driving minivans she deserves to drive a nice car.

Any input would be very much appreciated even if it's: sell it fast and get something simple you can afford

RA40

iTrader: (6)

Do you have the factory remotes? Original keys?

IMO, yank the aftermarket alarm and get the wiring back to normal. Why anyone would install a secondary system onto a car that already has remote lock-unlock capabilities is If the installer wasn't good then who knows how they hacked the system up.

foos

I do have 1 original master key but no factory remote. I agree, I would never have installed it myself. I'm thinking I should tow it to the alarm shop and see if I can get them to remove alarm and fix wiring. Maybe they can figure out way it's immobilized? I've been searching but haven't found anyone who's immobilizer unit went out. I may be wrong but still think something else may be at fault.

billydpowe

iTrader: (1)

My feelings are, you are in a trap, and I dont see an easy way out.
probably NONE of us have been in your situation.
Why anyone would install a secondary system onto a car that already has remote lock-unlock capabilities is, well, mentally slow. If the installer wasn't good then who knows how they hacked the system up. AND I think this is a good idea, tow it to the alarm shop and see if you can get them to remove alarm and fix wiring. BUT I doubt they will have the knowledge to get it running for you.
You are in a situation that is going to need electronic equipment to read and show what is wrong with it.
many of us are quiet, because we really dont know what to tell you. I have been on here since 2004, and this is the first problem of this type I have seen.
If you can, keep us posted on the outcome, for other readers.

RA40

iTrader: (6)

If this secondary system has an ignition kill, that is probably triggering the engine to shut off. Not knowing how they spliced into the system is a wild guess. You could try disconnecting power to the secondary alarm and see if it returns to normal.

If so you got off easy and you can just leave it. Then wander that auction site for factory remotes and buy as necessary. We have past threads on the remotes and programming here.

As billydpowe mentioned, this is the first I recall reading about a secondary system being installed into the Lex.

foos

So it's rare to see after market remote start or alarm on LS 400?

I called the shop and they said to drop it by and they'd take a look at it and remove it if needed. From the looks of thier site the do some pretty nice custom work so hopefully they have someone with tallent working there.

Thanks for the input guys. didn't realize it was such a unique situation. Will keep you posted on the outcome.

JimsGX

Foos,

I think you're on the right track thinking it's a problem with the aftermarket alarm. I have an aftermarket alarm / car starter in my 91. The wife of the previous (original) owner threw away the remote keys after her husband died. It was going to cost a considerable amount to get two new remote keys and a new computer chip in the trunk. I opted for the aftermarket w/starter which only cost around $240 installed and gave me the additional functionality.

The installer commented on the fact that the LS400 wiring was very similar to the Camry.

Anyways, I wouldn't give up on the car yet. I'm sure you'll get it sorted out for a reasonable price. In the 6+ years I've been on this site, I don't remember ever hearing of an immobilizer ECU failing. I'm sure its happened, but I think its very rare and the fact that the car starts tends to rule that out...

MicahBerry

Dumb question here, but would a low battery in the key fob (transponder?) affect the immobilizer?

I know it's not a Lexus, but the Mazda we just bought my daughter came with one factory key and one copy key. The copy key starts the car, which runs for two seconds, and then the engine dies. When I put the factory key in, the car starts and runs normally.

Anyway, good luck with the solution!

Micah

foos

good question...I've wondered if the key could have gone bad. Still not sure exactly how the immobilizer works. if after starting it tries to read key for 3-5 sec then cuts fuel, or keeps the engine from starting all together?

feeling pretty confident the alarm is at fault though. alarm shop is being less friendly since finding out I'm not the original purchaser. "lifetime warranty is non transferable". Towed it there anyways but have to wait till monday before they will look at it and will prob have to pay em 45/hour.

foos

Looks like all of our suspicions were correct. Alarm shop just called and said they removed alarm and it's running fine now. They weren't able to figure out why the door locks aren't working but I'll save that for another time. They charged $45 total and said if I send the alarm to manufacturer they will replace it with new one to sale or whatever. I'm sure if I pressed I could have gotten away with not paying anything, since they installed it only 3 months ago, but I am very thankful to have the car running again.

Thank a lot for the advice guys. Really helped me decide it had to be the alarm saving me an unnecessary trip to the dealer.

RA40

iTrader: (6)

Good...
See if you can pick yourself up some factory remotes off that auction site, here or your local Craigs List. So long as you have a master key, then we can go from there. Cost range from $15-$50.

MicahBerry

Glad you got it resolved!

Micah