My immobilizer fix (2 Viewers)

[medtro]

For the record - none of the kits I built every resulted in crank/no start but using various wire sizes and new and old relays they both got hot.

Thanks for the clarification. I thought it failed to start when you called not a permanent fix.

I built a couple of them - all 12-14 gauge wire. I don’t have pictures, but I built a couple with heat/crimp connectors and then soldered a couple more up.

Crimp connectors, heat crimp, etc. I didn’t solder the connections as I got good crimps and made sure of that.

I don't know which to believe.

I will crack open the fuse box eventually and post pictures. I agree with the amperage/voltage commments above - my point is - I am VERY sure the resistance that is resulting in higher heat, amperage increase, voltage drop, at least in my case, is in the fuse box.

Looking forward to the pictures. Can you please explain how amperage increases?

Direct to battery - no relay - and it gets hot.

We can debate wire size, but I used 14 and 12 and either one should easily handle 20 or 30 amps of 12v given the distance. In theory - it’s a voltage regulator only - at least to the ECU.

Not going to debate. You can search what wire size Toyota recommended for a 15A EFI circuit in FJ80 for similar issue.

I would call that a voltage divider, not voltage regulator.

If the issue is in the fuse box - the larger wire is only going to mask an underlying issue in the box.

If a larger wire solved your overheating issue, then I would view that as a solution, not masking. It is not a problem unless something starts to melt. FWIW, good wire and relay are rated for at least 185F.

 

[medtro]

Driving 30-45 mins a non-issue, but driving over an hour and they started to get hot. And by “hot” I mean they melted the heat shrink on the crimp connectors.

They all worked, but if I drove for a couple hours - they all increased in temperature.

I used one of the open fuse locations to power the relay and as you can see the post relay side is what got hot. Again - this was only on longer drives but in Texas it’s pretty typical to drive 3 hours and that’s when it was noticeable.

Why did the number of hours it took to melt the heat shrink keep changing? It went from 1 hour to 2 hours, then 3 hours.

 

[medtro]

I've been running the same thin wire with burn marks for 6 years now with no issues and is my DD. If it ever fails I will report back.

Your inbox is full. I would like to send you a free kit to run it in your DD.

 

[RoughOne]

Your inbox is full. I would like to send you a free kit to run it in your DD.

Please email me @ roughroad707@outlook.com
Thank you sir.

 

[medtro]

Driving 30-45 mins a non-issue, but driving over an hour and they started to get hot. And by “hot” I mean they melted the heat shrink on the crimp connectors.

They all worked, but if I drove for a couple hours - they all increased in temperature.

I used one of the open fuse locations to power the relay and as you can see the post relay side is what got hot. Again - this was only on longer drives but in Texas it’s pretty typical to drive 3 hours and that’s when it was noticeable.

I reached out to someone in Phoenix AZ who owns a bypass kit from me. I picked him because Phoenix temperature is warmer than San Antonio temperature and he drives a lot. I asked him if he has any heat shrink melted issue with the kit. Below is his reply. He is at 270k miles now. YMMV.

Since your kit, i've drven 10s of thousands. trips to California, back to east cost. So many extended hours. No issues. no meltage

 

[medtro]

Another cruiser owner in Dallas TX, who drives longer than 1-3 hours often, and more than 30k miles a year, has zero heat shrink melting issue with my bypass kit at 400k miles.

 

[medtro]

As I understand it - Toyota upgrade the output side of the fuse boxes in ‘02 so this issue us generally only a problem in the early 100 series.

This is the first time I read about Toyota upgraded the output side of the fuse box in 2002. Based on the information from people who purchased the kit, 2002 LC/LX is not immune to the problem described in the first post. If what you said is true, then upgraded output side of the fuse box didn't address the problem before the relay. Someone with 2002 LC just PM'd me today saying his mechanic told him he needs a new fuse box. May be a new fuse box that is improved in 2002 is not a permanent fix after all???

This is the first time I read about Toyota upgraded the output side of the fuse box in 2002. Based on the information from people who purchased the kit, 2002 LC/LX is not immune to the problem described in the first post. If what you said is true, then upgraded output side of the fuse box didn't address the problem before the relay. Someone with 2002 LC just PM'd me today saying his mechanic told him he needs a new fuse box. May be a new fuse box that is improved in 2002 is not a permanent fix after all???

This 2002 LC owner was instructed by his mechanic to order the kit. I will be sending it to the shop tomorrow.

The 2002 LC owner reported his 2002 Land Cruiser is alive again.

 

[medtro]

I will crack open the fuse box eventually and post pictures. I agree with the amperage/voltage commments above - my point is - I am VERY sure the resistance that is resulting in higher heat, amperage increase, voltage drop, at least in my case, is in the fuse box.

Looking forward to the pictures. Can you please explain how amperage increases?

Please explain how the resistance that is resulting in higher heat, increases the current in the circuit.

 

[Trunk Monkey]

I don't think he's going to respond, maybe let it go?

 

[medtro]

I don't think he's going to respond, maybe let it go?

Hopefully he will reply soon.

 

[RoughOne]

I received the kit from Medtro and could not be happier! This kit is the Golden ticket for the immobilizer fix!
Plug n Play and looks like it is built to last!

 

[2ruble]

So, here's the question, it's uncommon on 2003+ because of the new fuse box design, right? But, I have a 2005 LC and have started having the crank no start issues over the last couple months and it was getting - seemingly - progressively worse as it got hotter during the day. It's kind of intermittent in the mornings for me, below 70, but inevitably no matter the time of day, temperature outside, how long/short I've driven, or distance, or any other scenario, when it does happen, the vehicle will start up right away on the second attempt. I have read over this post now entirely, and will now be looking for the security light to blink when attempting to start so the next time it happens, I can report back accordingly. Looking over my fuse box, on the updated/2003+ models, it is an entirely different layout but looks like it's still a single fuse - albeit 25A now - and relay. Is that correct? Is there a fix for 2003+ if this does turn out to be my issue? Is there something else I should be looking for?

 

[Live to Ski]

have you cleaned the mass flow air sensor lately?

I believe your symptoms can indicate a needed cleaning. a one banana job. give it a whirl (pun intended)

 

[medtro]

So, here's the question, it's uncommon on 2003+ because of the new fuse box design, right?

Yes.

But, I have a 2005 LC and have started having the crank no start issues over the last couple months and it was getting - seemingly - progressively worse as it got hotter during the day. It's kind of intermittent in the mornings for me, below 70, but inevitably no matter the time of day, temperature outside, how long/short I've driven, or distance, or any other scenario, when it does happen, the vehicle will start up right away on the second attempt.

It sounds like sensor issue if it is temperature dependent. It also sounds like fuel pressure issue if it will start up on second attempt.

I have read over this post now entirely, and will now be looking for the security light to blink when attempting to start so the next time it happens, I can report back accordingly.

The blinking security light is not a good indicator in the newer model. I tested the bypass and was able to start with blinking security light.

Looking over my fuse box, on the updated/2003+ models, it is an entirely different layout but looks like it's still a single fuse - albeit 25A now - and relay. Is that correct?

Yes.

Is there a fix for 2003+ if this does turn out to be my issue? Is there something else I should be looking for?

The same bypass kit will work if you have the same issue like in the older models.

 

[2ruble]

have you cleaned the mass flow air sensor lately?

I believe your symptoms can indicate a needed cleaning. a one banana job. give it a whirl (pun intended)

I have, the first couple times this occurred, I went ahead and cleaned it and it didn't seem to impact it at all.

 

[2ruble]

@medtro thanks for that information. Thankfully, but not for diagnosing, the dozen or so times I've started the truck since making my post, it hasn't had an issue starting. I haven't checked anything fuel related; pump, filter, injectors, or otherwise. I guess I can start down the path of looking at those. And for a sensor if it is temperature related... do you have a recommendation as to where to start there?

 

[medtro]

@medtro thanks for that information. Thankfully, but not for diagnosing, the dozen or so times I've started the truck since making my post, it hasn't had an issue starting. I haven't checked anything fuel related; pump, filter, injectors, or otherwise. I guess I can start down the path of looking at those. And for a sensor if it is temperature related... do you have a recommendation as to where to start there?

Sensors that have helped other people fixed their crank no start problem: crank sensor, cam sensor, coolant temperature sensor, MAF sensor

 

[2ruble]

Sensors that have helped other people fixed their crank no start problem: crank sensor, cam sensor, coolant temperature sensor, MAF sensor

Alrighty, that's my list. I greatly appreciate this entire thread and then your individual guidance for me as well. Thanks others too.

 

[Live to Ski]

I have, the first couple times this occurred, I went ahead and cleaned it and it didn't seem to impact it at all.

at least you ruled that simple item out.

 

[2006 LX470]

I have a 2006 LX470 and have the occasional no start issues. It started about a 2 years ago on a trip out west and has been more frequent lately.

Every time it doesn't start, the security light is flashing. It cranks every time, but won't start due to the immobilizer. I try a bunch of different things, but usually just have to wait and keep inserting the key until the security light doesn't flash before it'll start.

The truck is a southern car with absolutely no rust on it. It currently has about 250k on it and I have owned it since 200k.

Any ideas what I could look at since it's not as common on the 03+ other than what is mentioned above? What can cause the light to keep flashing other than it not sensing the key?

This kit would work on an 2006, right?