fix for immobilizer issue? (1 Viewer)

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Unfortunately, this is where my knowledge wears thin - if I had to guess, I'd venture that I have spark as the truck has been running flawlessly since the day I got it (with only that one hiccup I mentioned above which happened for an hour, nearly two years ago), even taking it on a 200 mile round trip drive Sunday and it starting up no problem Monday morning when I had to move it out of the street sweeping zone... but that's the confusing part. No signs of anything wrong, even keeping with 15mpg on the highway the entire time.

That said, I will be heading to AutoZone tomorrow to pick up some starting fluid.

Other that that, any idea what could cause it to stop so suddenly? I'd always assumed that if a pump is failing, it'll happen over time and not on one day and off the next, literally 16 hours later with no signs and no use in between. I almost suspect that fact that since I filled the tank for the first time since June (my driving is very limited so 50-60 bucks to get me to 1/2 a tank every couple of weeks is normal), I'd inadvertently kicked up some debris in the tank which clogged the filter, but when I attempted to start it this past Tuesday, it didn't even sputter - it just wouldn't start in the same way it's not starting now. Nothings changed since the first attempt. So I just assume something died. But I have no idea what.

Also, I almost wish it was the relay because your bypass comes so highly rated and looks like such a slick piece of DIY engineering. I might actually pick one up anyway, to keep in my toolbox.

Thanks so much for your help
May be something has been failing over time and you just didn't know. Assuming you have spark and it starts with starting fluid, then you have fuel related issue. You don't have spark if it doesn't start with starting fluid. I was helping someone with intermittent crank and no start issue yesterday. He was able to start with starting fluid. It turned out his problem was bad fusible link. One of the circuits in the black box is blown.
 
Thanks for the response - yes, based on what I've read in the threads posted about the issue, everything I'm experiencing points away from the immobilizer / fuse / fusebox being the issue and more toward the fuel pump (security lights, CEL / Dash Lights, and and replaced fuses, etc)

Adding the fuel pressure gauge is a bit above my ability at the moment, not to mention, living in Los Angeles, mine is parked on a relatively busy street, across the street, and a couple of houses down, so it's not an idea place to get any good work done at the moment.

There are other ways to determine if your fuel pump has failed or is....failing. But due to your circumstances, it sounds as if you might do best to have it towed to a mechanic.

I don't think you are going to find your issue to be an easy 'roadside' fix. It is going to require some testing and diagnostics.

Then....short of replacing a fuse or relay.....it will entail some amount of tools and mechanical skills that might not lend themselves to fixing along a busy street.
 
May be something has been failing over time and you just didn't know. Assuming you have spark and it starts with starting fluid, then you have fuel related issue. You don't have spark if it doesn't start with starting fluid. I was helping someone with intermittent crank and no start issue yesterday. He was able to start with starting fluid. It turned out his problem was bad fusible link. One of the circuits in the black box is blown.

There are other ways to determine if your fuel pump has failed or is....failing. But due to your circumstances, it sounds as if you might do best to have it towed to a mechanic.

I don't think you are going to find your issue to be an easy 'roadside' fix. It is going to require some testing and diagnostics.

Then....short of replacing a fuse or relay.....it will entail some amount of tools and mechanical skills that might not lend themselves to fixing along a busy street.
SO, bit of an update.. I did as much as I could to get to the bottom of the issue until I ran out of patience and called a tow and sent it off to the shop sticking to my guns that it's the fuel pump. Got an update yesterday telling me they were going at it as if it were an ignition issue, which was surprising, but not unheard of.

Got a call today that confirmed it's the fuel pump so they're replacing that and the EFI relay which should solve the issue. I'm hoping to pick it up tomorrow or friday morning, so will further update once I get a few solid miles under the new pump.

Thanks everyone for the help.
 
Final (I hope) update on this issue for me. Shop replaced the EFI Relay and the Fuel Pump and we've been running strong since yesterday (and did I notice better fuel mileage??). I am going to give it a proper test drive today, but I wanted to thank everyone for their help and hopefully if / when this issue comes up for someone in the future, they can learn from this experience and it can help them diagnose possible causes and fixes.
 
I do not have any experience with the vsc light also lighting up, but I delt with the immobilizer problem for about 2 years. I had a box of 20 amp fuses I would rotate. Fuses ended up melting into my EFI socket. The fourms suggested replacing the relay box, but I refused to believe there was not something else causing the issue. Guess what I replaced the relay box in March and I have not had a problem since. I had the relay box sitting in my cruiser ready to replace myself when it went out for the last time at the wrong time. Shop installed mine, but it can can be done yourself. There are 4 or 5 (maybe 6) connectors on the botton of the relay box. It looked straight forward from looking at the replacement box.
I just replaced my EFI 20 and it started like a charm. Appreciate it gent's
 
Trying to post on a relevant thread...
**Edit , whoops I thought I was In the EFI relay fix thread . Maybe not so relevant here


Can anyone check their fuse box cover ( in the engine bay ) and confirm if there is supposed to be a seal?

I removed mine today for the first time just to see if I should blow the dust out .within the lid there appeared to be this crusty ring around the cover which is either a dried up seal or dirt .

Toyota still has this part aba. I figured it's worth replacing to help keep moisture out . I think others have noted some corrision in that fuse panel.
 
Trying to post on a relevant thread...
**Edit , whoops I thought I was In the EFI relay fix thread . Maybe not so relevant here


Can anyone check their fuse box cover ( in the engine bay ) and confirm if there is supposed to be a seal?

I removed mine today for the first time just to see if I should blow the dust out .within the lid there appeared to be this crusty ring around the cover which is either a dried up seal or dirt .

Toyota still has this part aba. I figured it's worth replacing to help keep moisture out . I think others have noted some corrision in that fuse panel.

Like this?
 
Like this?
Bahhh there it is. Shoot I just spent 80 bucks ordering a new top from Toyota. Great shame on me
 
chalk up another "EFI fuse jumper" to the rescue. My 2000 LC (255k) presented the immobilizer issue a couple weeks ago, but started shortly thereafter. Today, I made it halfway to work, stopped for coffee, and it would not start. Had the SO bring me a different set of keys (hoping it was a key-chip issue) and still no fire. Found this thread - and with a paperclip jammed in the fuse slot she fired up. Will clean out the contacts and try some new fuses, otherwise, may lean on the jumper permanently.
 
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I have had this issue a few times. 100% it's the EFI fuse. I keep a packet in my car. Seems to go out once or twice a year for a no-start. If I replace the fuse even if it looks OK it starts right up.
 
In my case, I thought it might have been a blown fuse, but after a lot of investigation, it wasn't the fuse itself but it was the fuse holder (clips). I was able to patch together a temporary solution, but installing the EFI Jumper solved it .
 
^ same problem I experienced: It toasted the fuse holder in the fuse box. By the look of mine I was lucky it didn't start a fire.
 
^ same problem I experienced: It toasted the fuse holder in the fuse box. By the look of mine I was lucky it didn't start a fire.
other than "replacing the fuse box" what is the ultimate issue/fix?
 
Move to a newer UZJ100? I think they separated the EFI slot into 2 fuse slots in '03? Not sure on the MY for that...

IMO, a new fuse box just delays the inevitable problem.

@medtro workaround completely addresses Toyota's design flaw.
 
I have a 2004, is this something I should be concerned about? No problems that I know of.
 
You can change the EFI fuse in the relay/fuse box under the hood. Change the fuse even if it looks good.
Saved my bacon stranded in town today. EFI fuse completely nuked - even plastic burned to a crisp. Thanks again for the gurus on this forum.
 
2000 LC with 248k. Got gas the other day and truck wouldn't start. Cranked super strong but no fire. Found this thread and was able to jump into the fuse block and start working towards a solution. Five hours from home and after cleaning the contacts and a new fuse it got us back to our driveway.

I ended up removing the faulty extension pins/standoffs and soldering an inline micro fuse directly to the posts. I reinstalled the fuse box without EFI fuse, truck cranked wouldn't start. I put the fuse in and it started right up so I think this is a fix.

Anyone mind auditing my work below to help me catch any oversights in this fix?

Removed the fuse box (which I later figured I probably didn't have to do):

IMG_6922.jpeg



From here I removed all the fuses and stripped it down, I was planning on taking the whole box apart but then I thought I might try and expose the EFI fuse connection from the top by removing some material around the fuse holder. I slowly cut away material (should have grabbed a Dremel?) and eventual exposed the two posts that connect the fuse to the lower contact points:
IMG_6925.jpeg


The two posts that connect to these terminals are pictured below, the one the right is discolored from heat it looks like, both were quite loose and wobbled around on the posts.
IMG_6924.jpeg



I found an inline fuse kit from the auto store and decided to solder this in
IMG_6928.jpeg


I covered the area with brush on electrical tape, reinstalled all the fuses and installed back in the truck.
IMG_6933.jpeg


I feel pretty confident I solved the EFI fuse terminal connection issue that was causing issues. Is there anything else I might have overlooked by doing this DIY?
 
2000 LC with 248k. Got gas the other day and truck wouldn't start. Cranked super strong but no fire. Found this thread and was able to jump into the fuse block and start working towards a solution. Five hours from home and after cleaning the contacts and a new fuse it got us back to our driveway.

I ended up removing the faulty extension pins/standoffs and soldering an inline micro fuse directly to the posts. I reinstalled the fuse box without EFI fuse, truck cranked wouldn't start. I put the fuse in and it started right up so I think this is a fix.

Anyone mind auditing my work below to help me catch any oversights in this fix?

Removed the fuse box (which I later figured I probably didn't have to do):

View attachment 3434242


From here I removed all the fuses and stripped it down, I was planning on taking the whole box apart but then I thought I might try and expose the EFI fuse connection from the top by removing some material around the fuse holder. I slowly cut away material (should have grabbed a Dremel?) and eventual exposed the two posts that connect the fuse to the lower contact points:
View attachment 3434243

The two posts that connect to these terminals are pictured below, the one the right is discolored from heat it looks like, both were quite loose and wobbled around on the posts.
View attachment 3434245


I found an inline fuse kit from the auto store and decided to solder this in
View attachment 3434246

I covered the area with brush on electrical tape, reinstalled all the fuses and installed back in the truck.
View attachment 3434247

I feel pretty confident I solved the EFI fuse terminal connection issue that was causing issues. Is there anything else I might have overlooked by doing this DIY?
I like this fix. Seem like a good permanent solution.
 
Just curious if I might be falling victim to the same issue...

Have had my '00 for (200k miles) for a couple months now and it has always started up no issue. Weather got colder and starting this weekend, I put my key in and when attempting to start it, all the electronics fire up and work fine but nothing from the engine. I have programmed new keys, so I am familiar with the engine trying to turn over and never starting if the chip isn't programmed....but this isn't the same, as the engine doesn't crank with this issue..just nothing happens (other than all electronics coming on an working fine).

It started 100% of the time without any hesitation until this weekend where it didn't. I pulled the key, re-entered it and it started up. Then a day later, I ran some errands, same thing. Then that evening, I thought I was stranded at work as it took several key re-entries to get it to start up (when it does, it starts right up). Then this cold morning, no amount of retrying would start it (have tried all my keys, cycled the alarm/door lock several times)

Could this still be fuse/fuse box related or should I be looking into other issues?
 

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