1997 ECU Replacement - immobilizer concerns
05-19-14, 02:48 PM
#1
Driver School Candidate
Thread Starter
1997 ECU Replacement - immobilizer concerns
Alright.... have a dumb question here... probably dumb to you guys, but as a newb to the LS400 I'm a bit worried. My 97's ecu was damaged by leaking caps so I had purchased another one and sent it off to be recapped with the appropriate upgrades from the list and am waiting on it to be shipped back as of today.
The original ecu was 50340, but am replacing it with the later version 50341 which I hopefully did right on that. However, as most will know this car has the immobilizer though it's separate from the ecu. So my question is will I have issues with the car starting or is this going to require dealership or locksmith help? I have the original keys, but don't know how the separate immobilizer works vs the ecu with the built-in immobilizer. I've been trying to find, but to no avail and the info on the immobilizer aspect is somewhat confusing.
The original ecu was 50340, but am replacing it with the later version 50341 which I hopefully did right on that. However, as most will know this car has the immobilizer though it's separate from the ecu. So my question is will I have issues with the car starting or is this going to require dealership or locksmith help? I have the original keys, but don't know how the separate immobilizer works vs the ecu with the built-in immobilizer. I've been trying to find, but to no avail and the info on the immobilizer aspect is somewhat confusing.
Last edited by RA40; 05-19-14 at 04:05 PM.
05-19-14, 05:36 PM
#2
Moderator
An ECU needs a matched bit stream code which is the same as the one sent from the key. Another used ECU needs to be re-writen the data stored at the non-volatile memory in the ECU. This needs a special tool and some skill.
The best way may be to ask a dealership to do it. Some locksmiths can do that too. There's a way to start the engine without doing that but it's a confidenial and I have no idea to write it here.
The best way may be to ask a dealership to do it. Some locksmiths can do that too. There's a way to start the engine without doing that but it's a confidenial and I have no idea to write it here.
Sounds like I'm a bit screwed. Guess I better make preparations. Thanks for the info anyways.
05-20-14, 01:58 AM
#7
Driver School Candidate
Thread Starter
Waiting for the Toyota dealership to contact me some time today to see. No Lexus dealership here. I suppose that makes no difference, but I'm preparing for the worst since the car will have to be towed.
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05-20-14, 03:22 AM
#8
Moderator
How much damage does your 97's ECU have?
How was the last status of your car?
Was it totally dead?
The reason I ask you is that I need to know those to judge your original ECU can be fixed or not.
I have been fixing different ECUs at near by shops for free and now I know the limit whether the ECU can be fixed or not.
How was the last status of your car?
Was it totally dead?
The reason I ask you is that I need to know those to judge your original ECU can be fixed or not.
I have been fixing different ECUs at near by shops for free and now I know the limit whether the ECU can be fixed or not.
05-20-14, 05:47 AM
#9
Driver School Candidate
Thread Starter
The car started to exhibit rough or delayed starting until it finally wouldn't start anymore, just turnover. When I removed the ecu and examined the internals I found at least one to two caps with leg corrosion, but a third cap had completely leaked out and ate up another very small component and looked like it ate a small trace. I believe it was the cap in the C104 area.
In having the replacement ecu recapped the repairman offered to knock off the price if I sent in the old unit as he wanted to see if he could repair it. He mentioned the part that was ate up was a snubber cap. I have since contacted him while the package is on it's way to me tomorrow. I alerted him of the situation and he offered to swap ecus if it was too costly to have the one I bought flashed.
Guess I made a big mess of things.
In having the replacement ecu recapped the repairman offered to knock off the price if I sent in the old unit as he wanted to see if he could repair it. He mentioned the part that was ate up was a snubber cap. I have since contacted him while the package is on it's way to me tomorrow. I alerted him of the situation and he offered to swap ecus if it was too costly to have the one I bought flashed.
Guess I made a big mess of things.
Last edited by Diwill05; 05-20-14 at 05:50 AM.
05-20-14, 07:46 AM
#10
Best of luck and keep us posted!
05-20-14, 08:08 AM
#11
Driver School Candidate
Thread Starter
Yeah I was hoping it was something simple, but other random electrical problems started occurring that wasn't there before... tach, speedometer would randomly work, would start fine one minute, then next it would take several attempts, then back to not start at all. Real random stuff.
The ecu will be here tomorrow, but if toyota doesn't contact me or if no locksmith can program it then I will trade back out for the original one assuming it's been repaired properly. Wish I had known about this immobilizer crap. Never would have bought it.
The ecu will be here tomorrow, but if toyota doesn't contact me or if no locksmith can program it then I will trade back out for the original one assuming it's been repaired properly. Wish I had known about this immobilizer crap. Never would have bought it.
05-20-14, 11:37 AM
#12
If the remaining aspects of the car are 
getting the ECU fixed and programmed is still worth it. A dealer purchased ECU is a substantial cost to the value of the car.
What makes me curious next is can a '97 be converted to the 95-96 in that electronics area?
getting the ECU fixed and programmed is still worth it. A dealer purchased ECU is a substantial cost to the value of the car. What makes me curious next is can a '97 be converted to the 95-96 in that electronics area?
05-20-14, 01:45 PM
#13
Driver School Candidate
Thread Starter
Update: Toyota says no... they don't have the capabilities, locksmith doesn't either, import garage...no, etc... I guess I need to skin some bears and tote a club being in a stone age town. I am making arrangements to get back the original ecu and just deal with this nightmare.
05-20-14, 01:56 PM
#14
Driver School Candidate
Thread Starter
The car runs out good & quiet.. idled good, everything worked except the changer went out a month or two ago, mileage is 179,000 and had Toyota do an inspection with a synthetic oil change so there's plenty of life left I feel. Just irritating this problem is. I just want to get it fixed & move on to other things like tint, refurbish the stereo, etc so I can enjoy the car.
05-20-14, 04:51 PM
#15
Moderator
With that situation, your ECU must have no idea to work properly. The very small component in the C104 area must be a ceramic capacitor but in order to give you a more detailed suggestion I need a clear photo to judge and to know how the traces are damaged. In the past I have fixed some ECUs that had damaged other components as well as lost some traces. I have needed to replace components assuming the value and also rewired those traces. The rsults were all successful except one but I have needed to spend many hours sometimes nealy a day.