My immobilizer fix (2 Viewers)

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Bought a 2001 LC today and tonight it stranded me twice with this issue. I just waited long enough for it to cooperate and all was well, but it appears I have the same issue. I’m going to read this thread very carefully when I’m back home and probably order this immobilizer kit you speak of. Any other quick tips?
 
is there anything that can be done to prevent this issue from happening ? Like cleaning / greasing the EFI relay contacts or replacing the EFI relay proactively?
 
Bought a 2001 LC today and tonight it stranded me twice with this issue. I just waited long enough for it to cooperate and all was well, but it appears I have the same issue. I’m going to read this thread very carefully when I’m back home and probably order this immobilizer kit you speak of. Any other quick tips?
The kit will eliminate this fuse isssue. However, as an emergency use for starting the vehicle, you can run a fused wire from the battery straight to relay slot "E", as pictured in the first post. This will get you cranked up but take it out when not running due to battery drainage.
 
The kit will eliminate this fuse isssue. However, as an emergency use for starting the vehicle, you can run a fused wire from the battery straight to relay slot "E", as pictured in the first post. This will get you cranked up but take it out when not running due to battery drainage.
I would try slot "F" if you are using my picture as slot reference.
 
So, after running medtro's bypass kit it all worked great. Until yesterday. Backstory: Years ago the A/B EFI fuse location melted where I only had the means of connecting to the "B" side. But, yesterday while en route to Death Valley, the engine died. I was able to get it going again by increasing the friction holding the bypass' blade into the B side of the fuse slot by utilizing a female pin adapter. But that only lasted a few miles when the engine died once again. I eventually, because I had no tricks left in my proverbial bag of tricks (it happened yesterday on Halloween of course :rolleyes:...pun intended LOL), soldered the connecting pins/blades to hopefully eliminate vibration and subsequent shorting... thinking the problem was the interface between the two blades, only to have the engine die once again after a few miles further down highway 395.

I couldn't resurrect it so had to get it towed home. I'm guessing, this time, the short has occurred on the bottom side of the fuse box at the A/B fuse link/connector/? interface.

It will be a while before I have time to deal with it...but presumably will have to swap in a new fuse box. Oy vey.

I haven't searched yet, as I swapped the spressoWAGON for the LBZ Duramax and am currently camped out near Bishop for a week of hiking, etc., instead of being with my buddies in Death Valley, but wondering if there is a better more protected/longer lasting solution to this Toyota shortcoming than swapping in another OEM fuse box when "we" and I already know its problematic.
 
In almost 20-years and 200,xxx miles I've put on the spressoWAGON, its never been tow trucked. Strapped, yes but never flat bedded.

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So, after running medtro's bypass kit it all worked great. Until yesterday. Backstory: Years ago the A/B EFI fuse location melted where I only had the means of connecting to the "B" side. But, yesterday while en route to Death Valley, the engine died. I was able to get it going again by increasing the friction holding the bypass' blade into the B side of the fuse slot by utilizing a female pin adapter. But that only lasted a few miles when the engine died once again. I eventually, because I had no tricks left in my proverbial bag of tricks (it happened yesterday on Halloween of course :rolleyes:...pun intended LOL), soldered the connecting pins/blades to hopefully eliminate vibration and subsequent shorting... thinking the problem was the interface between the two blades, only to have the engine die once again after a few miles further down highway 395.

I couldn't resurrect it so had to get it towed home. I'm guessing, this time, the short has occurred on the bottom side of the fuse box at the A/B fuse link/connector/? interface.

It will be a while before I have time to deal with it...but presumably will have to swap in a new fuse box. Oy vey.

I haven't searched yet, as I swapped the spressoWAGON for the LBZ Duramax and am currently camped out near Bishop for a week of hiking, etc., instead of being with my buddies in Death Valley, but wondering if there is a better more protected/longer lasting solution to this Toyota shortcoming than swapping in another OEM fuse box when "we" and I already know its problematic.
I didn't know you were connecting to B, it should be A to start with. Can you try connecting the kit straight to the battery instead of A or B?
 
After towing the 100 back home I swapped into my Silverado. I'm out camping in the Eastern Sierra for the next 10-days and will try powering your kit direct to the battery and see how it goes.

Thank you!
 
In almost 20-years and 200,xxx miles I've put on the spressoWAGON, its never been tow trucked. Strapped, yes but never flat bedded.

View attachment 3763168
I thought you got out of 100 series ownership 6-7 years ago? Apparently I wasn’t paying attention!
 
Yeah, it was a thought about 7 years ago but it refused to leave me 😂
 
Hi Medtro
I sent an email to you Gmail address. I am having trouble sending a PM to you. It may be because I just created my account.

Thanks
Chris
 
I got the famous crank but not start immobilizer problem. I replaced the 20A EFI fuse with a 30A fuse and it started right away. However, it was a temporary fix. I had the same problem again 4 days later. This is what I did to get the engine started. It has been working with no problem for close to 4 weeks now, I thought I would share this with the group.

Fuse terminals: A, B
EFI relay terminals: C, D, E, F

View attachment 1311409

With the EFI fuse in place and relay removed, I ran a wire from the battery positive terminal to terminal F, engine started with no problem. This tells me problem was at upstream or bad relay.

PS: This is a good wire to have in the car for emergency fix.

View attachment 1311410

Factory EFI relay tested good. Next, I shorted terminals E and F, engine cranked but not started. This tells me the power from terminal E was not good enough to start the engine. With the help of voltmeter, I found out there was 0.44V voltage drop between the battery and terminal E with factory 20A fuse in place. Voltage drop was 0.14V with 30A fuse. The engine wouldn't start even with 0.14V voltage drop. I came up with the following to bypass the internal circuit between terminals B & E in order to reduce the voltage drop between the battery and terminal F.

I used a Tyco V23234-A1001-X043 Mini Relay 12V. Make sure the relay you use has suppression protection if you are going to do this, otherwise this could cause damage to your ECM.

Wiring diagram:
Terminal A to 20A inline fuse to terminal 87 of Bosch relay
Terminal F to terminal 30 of Bosch relay
Terminal C to terminal 85 of Bosch relay
Terminal D to terminal 86 of Bosch relay
No connection for terminals B and E

Factory EFI relay can be used in this setup. I used Bosch relay because I want the relay to sit flat in the fuse box. I also put a piece of high density foam between the fuse box cover and Bosch relay to "secure" it better in place.

View attachment 1311417
View attachment 1311418
So i just had this issue and found this post. The jumper wire allowed it to start. I found the "A" terminal was black and corroded. I cleaned it up and for now it is working. I am curious if the relay mod will fix this problem as the "A" Terminal is the power source right?
 
So i just had this issue and found this post. The jumper wire allowed it to start. I found the "A" terminal was black and corroded. I cleaned it up and for now it is working. I am curious if the relay mod will fix this problem as the "A" Terminal is the power source right?
You can power the kit from the battery, this will avoid issue from "A" terminal.
 
Just adding to the collective knowledge that if your key breaks while starting, And then you use just the metal keyed part (no fob) to try to start, it’ll do a great impression of the Immobilizer issue. At one point I even had the fob in the cup holder, but that’s not close enough. Started once I held the fob next to the key while starting.
 
Just adding to the collective knowledge that if your key breaks while starting, And then you use just the metal keyed part (no fob) to try to start, it’ll do a great impression of the Immobilizer issue. At one point I even had the fob in the cup holder, but that’s not close enough. Started once I held the fob next to the key while starting.
Yes, same symptom. However if you do the battery to "F" test, it will tell you that you have a different problem.
 
Worst part is I did the battery to F test and ignored the result. The battery was weak and I was only getting a few tries per charge of the portable jump starter. In the past I have had the “real” immobilizer issue which was solved by changing fuses, so I know the fuse box in on borrowed time. Turns out it’s just not quite there yet. But glad I’ll have a bypass kit for when the time comes.
 
I have this problem (I think), I just posted about a no-start apparent immobilizer issue I have. For the "emergency" fix described in this thread, it is as simple as a male spade connector on the "F" relay terminal and length of wire to the positive post on the battery? Do I need to put on inline fuse on that wire? If so, 20A? Do I leave the wire connected once started/running, and then disconnect when I'm home? Sorry if some of these are dumb questions, but I'm an hour from my truck and I want to make sure I have what I need when I get back to it tomorrow. I have a fairly good collection of 12V wiring parts for working on my boat, but I don't want to get out there and find I need a part I don't have.
 
I have this problem (I think), I just posted about a no-start apparent immobilizer issue I have. For the "emergency" fix described in this thread, it is as simple as a male spade connector on the "F" relay terminal and length of wire to the positive post on the battery? Do I need to put on inline fuse on that wire? If so, 20A? Do I leave the wire connected once started/running, and then disconnect when I'm home? Sorry if some of these are dumb questions, but I'm an hour from my truck and I want to make sure I have what I need when I get back to it tomorrow. I have a fairly good collection of 12V wiring parts for working on my boat, but I don't want to get out there and find I need a part I don't have.
You don't need a fuse but I would add a 20A fuse. I would use 10 AWG wire for driving such a long time. Leave it connected once started, make sure it is securely connected otherwise the engine will stall. Disconnect the jumper from the battery when engine is not running to prevent battery from draining. Bring picks or small screw drivers for removing stubborn relay.
 
Temporary fix implemented, I’m pulling the inline fuse to disconnect when parked. Thanks! This forum never ceases to amaze me.

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