EFI Relay Bypass Kit (Immobilizer Fix) for UZJ100/LX470 (2 Viewers)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

are we connecting this to the negative or positive post of the battery?
The wire goes from positive battery terminal to the F region. i currently have a wire running til the kit comes in the mail. But does this mean i will need a new fuel pump or just wiring wrong?
 
The wire goes from positive battery terminal to the F region. i currently have a wire running til the kit comes in the mail. But does this mean i will need a new fuel pump or just wiring wrong?

You are not protected by any fuse with the wire connected. Plus it will drain your battery when parked. This means you have a bad fuse box.
 
I just experienced this same problem. Left me stranded on mountain late at nite.
Thankfully tow truck came out and saved me. Towed me 60 miles home.
My mechanic was able to figure a quick and simple bypass that seems to be working so far. Do not know if it it safe or if it will continue working. Will keep you posted.
 
I just experienced this same problem. Left me stranded on mountain late at nite.
Thankfully tow truck came out and saved me. Towed me 60 miles home.
My mechanic was able to figure a quick and simple bypass that seems to be working so far. Do not know if it it safe or if it will continue working. Will keep you posted.
Just order the kit works like a charm.
 
I wanted to post my experience with this issue and remoting the relay as Medtro's kit does, because it might help someone down the line that is tearing their hair out like I was a few days ago.

I bought Medtro's kit when my 100 first started having the immobilizer issue. Installed the kit, everything was happy as a clam for about a month. Then all of the sudden one morning, the issue came back. Only this time, the immobilizer light wasn't blinking with the key in, the truck just didn't fire. For fun, I swapped in the original relay and a fuse, the truck still didn't start, but this time the immobilizer light was blinking with the key in. I wrote that off as my relay was shot or something, and got out my multi-meter and started checking the fuel pump, wiring, all the ignition stuff, CAS, etc. All was within spec, which made sense the truck showed no symptoms up to just not starting.

Finally, out of curiosity and desperation I stuck the multi meter on the A and B pins shown below (where the EFI fuse goes, and how Medtro powers the relay with his kit). I got 8.18v, it should obviously be 12+. I ended up having to add a line direct from my battery and replace the wire from A to B to the remote relay, and now it's working great. I guess the short in the fuse box eventually gets worse. Hope this helps someone in the future. It's a head scratcher.

Connect a wire from battery 12V post to the F terminal (see picture below), then try to start the engine. This kit will not help if the engine doesn't start with the above wire connection (assuming the battery is fully charged). This is the kit you need if the engine starts.

fusebox1-jpg.1311409
 
Last edited:
I wanted to post my experience with this issue and remoting the relay as Medtro's kit does, because it might help someone down the line that is tearing their hair out like I was a few days ago.

I bought Medtro's kit when my 100 first started having the immobilizer issue. Installed the kit, everything was happy as a clam for about a month. Then all of the sudden one morning, the issue came back. Only this time, the immobilizer light wasn't blinking with the key in, the truck just didn't fire. For fun, I swapped in the original relay and a fuse, the truck still didn't start, but this time the immobilizer light was blinking with the key in. I wrote that off as my relay was shot or something, and got out my multi-meter and started checking the fuel pump, wiring, all the ignition stuff, CAS, etc. All was within spec, which made sense the truck showed no symptoms up to just not starting.

Finally, out of curiosity and desperation I stuck the multi meter on the A and B pins shown below (where the EFI fuse goes, and how Medtro powers the relay with his kit). I got 8.18v, it should obviously be 12+. I ended up having to add a line direct from my battery and replace the wire from A to B to the remote relay, and now it's working great. I guess the short in the fuse box eventually gets worse. Hope this helps someone in the future. It's a head scratcher.


Can anyone follow up about having to route a line from the battery? And supply some photos? I’m likely buying the kit but want it bulletproof.
 
Can anyone follow up about having to route a line from the battery? And supply some photos? I’m likely buying the kit but want it bulletproof.

I know a few has done this hopefully they will post pictures. It is basically instead of connecting to the EFI fuse slot, you connect the wire to the positive battery terminal.
 
Its been over 5 months since I installed the immobilizer and no issues. Fires up every time like a charm.
 
This bypass kit bypasses the bad EFI relay circuit in the fuse box so that the immobilizer system gets adequate power supply for starting the car. I made this for myself after my new 30A replacement fuse - initial fix for crank but not start problem, failed to start after 4 days. Some members have showed interest in the kit and asked me to sell this kit.

This bypass kit is for you if:
  • You are told a new fuse box 82720-60023 will fix your intermittent starting problem but you don't want to spend $460 just for the part alone
  • You have intermittent starting problem and you replaced the 20A EFI fuse with 30A fuse or paper clip
  • You have intermittent starting problem and you have been tapping or removing/replacing relays and fuses in the fuse box
  • You want to have this kit in your glove compartment in case you run into this crank and non starting problem
This kit is 100% plug and play, no need to splice any wires.

Kit comes with relay, two fuses (one for spare) and installation instructions. $83 shipped to 48 states. PM for payment info or shipping cost outside 48 states.

Different Tyco relay (with same capabilities) and fuse holder are used in the kit since the following picture is taken. The kit you will be getting will not look identical as shown in picture below.

View attachment 1330817

Ok, so my 2000 LX470 just had this issue and now it’s not wanting to start at all. I turn the key all the dashboard lights come on and then when I want to start there’s nothing, no cranking. How can I fix this on my own? What troubleshooting steps should I take. If someone can let me know since I need the vehicle and can’t wait until the part would get shipped. Thanks
 
Last edited:
Ok, so my 2000 LX470 just had this issue and now it’s not wanting to start at all. I turn the key all the dashboard lights come on and then when I want to start there’s nothing, no cranking. How can I fix this on my own? What troubleshooting steps should I take. If someone can let me know since I need the vehicle and can’t wait until the part would get shipped. Thanks

You may want to post your issue at 100-Series Cruisers technical forum.
 
This bypass kit bypasses the bad EFI relay circuit in the fuse box so that the immobilizer system gets adequate power supply for starting the car. I made this for myself after my new 30A replacement fuse - initial fix for crank but not start problem, failed to start after 4 days. Some members have showed interest in the kit and asked me to sell this kit.

This bypass kit is for you if:
  • You are told a new fuse box 82720-60023 will fix your intermittent starting problem but you don't want to spend $460 just for the part alone
  • You have intermittent starting problem and you replaced the 20A EFI fuse with 30A fuse or paper clip
  • You have intermittent starting problem and you have been tapping or removing/replacing relays and fuses in the fuse box
  • You want to have this kit in your glove compartment in case you run into this crank and non starting problem
This kit is 100% plug and play, no need to splice any wires.

Kit comes with relay, two fuses (one for spare) and installation instructions. $83 shipped to 48 states. PM for payment info or shipping cost outside 48 states.

Different Tyco relay (with same capabilities) and fuse holder are used in the kit since the following picture is taken. The kit you will be getting will not look identical as shown in picture below.

View attachment 1330817
How do I contact you to get this kit?
 
The kit does more than just replacing the EFI relay. As mentioned before the bad circuit is not used to power the relay. Your argument is based on ignoring the fact that the relay is powered from different source. We will not accomplish anything here until you stop insisting the EFI relay is bad and understand that the problematic circuit in the fuse box is bypassed.

I encourage you to read my technical thread in the 100 series forum. All trouble shooting steps are showed in that thread, and I also showed that the EFI relay was not the problem. There is also a member who used my schematic to bypass the bad circuit with factory relay and solved his non-starting problem. Hope this helps!
What is the technical thread called?
 
The kit does more than just replacing the EFI relay. As mentioned before the bad circuit is not used to power the relay. Your argument is based on ignoring the fact that the relay is powered from different source. We will not accomplish anything here until you stop insisting the EFI relay is bad and understand that the problematic circuit in the fuse box is bypassed.

I encourage you to read my technical thread in the 100 series forum. All trouble shooting steps are showed in that thread, and I also showed that the EFI relay was not the problem. There is also a member who used my schematic to bypass the bad circuit with factory relay and solved his non-starting problem. Hope this helps!
Where can I find the above mentioned thread?
 

Users who are viewing this thread

Back
Top Bottom