Another no-start/immobilizer thread–worn ignition? Remote start?

New here, but sadly I don't think I'll be around very long. I'm representing my parents' 2008 5.7L Navy Blue Tundra. We love the truck, but never use it for truck duties, and it has a no-start issue that's really getting irritating. We're looking to sell it but have to fix it first.

It seems like the typical crank-but-no-fire issue that lots of people around here have seen. The issue seems to come and go randomly, whether hot or cold. Sometimes it fires up after a few tries, sometimes it's bad enough we have to let it sit for hours before it'll work again. We've had it towed once. The shop said there was an immobilizer error code stored.

My first thought is the TSB# T-SB-0078-09 regarding replacement of the security ECU on the 07-08s. However, there are two wrenches in this plan:

This truck has an AstroStart remote starter installed, with a switch under the dash to turn it on and off. We don't have the remote for it, so we have no idea if it even works. Flipping the switch doesn't seem to make a difference. Furthermore, I'm worried that if somebody installed a remote start, the immobilizer system might have been messed with in some way that a computer replacement wouldn't solve.

Second thing I noticed is that the ignition cylinder seems to have spotty electrical connection to the key. If I put the key in, leave it in OFF and push it upward, the immobilizer light keeps blinking. If I push the key toward the floor, the light stops blinking. If the doors are open, pushing up stops the door chime, and pushing down makes it chime as expected. However, none of these actions seem to influence when the truck does or does not want to start.

Are there any diagnostics I can run on the ignition? Hate to pull the dash for an ECU swap if it's just a shoddy cylinder or antenna module.

Other than that, once it actually starts, it runs perfect. Great motor. I'll be sad to see it go.

Thanks in advance for your help.

 

Anybody?

 

The first thing that comes to mind to me is that the vehicle is intermittently recognizing the ignition key. The key has a chip in it that the ring around the ignition cylinder reads. One or the other could be at fault. Realistically it could be something else, but you mention that you wiggling or putting pressure on the key while in the cylinder makes me want to start looking there. The easiest thing to try would be another key, do you have one? The next would be the antenna around the ignition cylinder.

 

I should have mentioned in the OP, I have tried the second key. Nothing seems to make a difference when it's having one of its no-start fits.

Are there any diagnostics I can run on the antenna or cylinder itself?

 

I would guess that the "security/immobilizer" aspect of it is the antenna ring and key communication, or in this case, what seems to me to be a lack thereof. It doesn't sound to me that it's a mechanical malfunction. The additional bit of information of this happening with either key draws my attention to the antenna ring. What I would do to try to verify, or narrow it down more so, would be to remove the bottom half of the steering column cover. Put one of the keys in the ignition in the off position. Open the door so you can hear it ding, and hope that it doesn't. If it doesn't, that means there's no communication. If it does ding, wiggle it till it doesn't. Then I would take something non-electrically conductive and narrow, like a plastic toothpick or similar size. Then I would gently press on the antenna ring and the wires that are plugged into it listening for the ding to return. This is somewhat of an old school technique from back in the days when slapping the TV was used to get it working again, but it's subtler. It also requires a gentle, precise touch and patience. Once you get the hang of it, the technique can be used to find bad solder joints on a circuit board. You should be able to wiggle one wire at a time if you're adept. If you find a spot that makes the the sound return, you've found your problem. Alternatively, you could just take a gamble and replace the antenna. It's actually very easy, I've done it on my truck to replace the one that came with it to one that has an illuminated ring. You may find that you need to try to follow the wiring harness a little way to see if there's an fracture in a wire somewhere else in the circuit. It's possible that somewhere along the harness that there's a wire spliced into it for the aftermarket remote start. But I still think that you'll have the best luck by the antenna as wiggling the key can bring it back, as you've mentioned. Alright, I'm rambling...

 

In typical fashion, it works perfectly fine when I'm trying to diagnose it. It's been over a week now and the truck has behaved completely normal. I cannot reproduce the problem at all. It'll likely stay this way until somebody drives it a decent distance from home, then it'll have to be towed back.

 

Remote starts tie into ignition wiring and also tie into immobilizer. If you have no need for the remote start and don’t have a remote, pull it out as the first step to trouble shoot. Depending on when the remote start was installed would also dictate what immobilizer bypass module was used which would would dictate whether the installer had to tie into the immobilized by cutting/splicing the wires Or just tapping into the immobilizer system.

 

Reminds me of the time I was replacing the ignition key cylinder for a friend because it was wearing out and wouldn't reliable rotate. To remove the cylinder you needed to turn the key to the RUN position without starting the vehicle. I tried to accomplish this for a solid 45 minutes. The truck owner stopped by to check on how things were progressing and I explained the hold up. He got it first try...

 

I had a remote start on my Celica, while it was nice and fun and cool, after years of wear on the system it began to decline, starting like this, it would't start or read anything... I dropped off my car at my mom's place while I moved cross country for a job and my brother ended up yanking the whole system out due to so many issues trying to get it to turn on, as well as killing the battery. I would second this motion in yanking that system out and start fresh, just ensure you're covering any exposed wires.

 

Removing it ain't gonna happen... It's so spliced in there I can't tell where the aftermarket crap ends and the factory stuff begins. There are also a few bare wires just hangin' out, can't imagine where those used to go.

It does have a KEY-OVERRIDE-SL2 module in there, branded iFar.ca, which redirects to Fortin now. This system must have been installed a loooooong time ago, maybe when the truck was new. But I doubt the dealer did it because the on/off switch for the remote start system is just hack screwed to the dash panel. Maybe a dealer WOULD install it ghetto-style, I don't know.

For what it's worth, unplugging the key override module didn't change anything. Truck still starts. I've been stopping and starting it all afternoon with both the keys and not a hint of trouble.

I even got Techstream and one of those OBD-USB cables. I can see the live data feed from the immobilizer ECU. Says everything is peachy and no trouble codes to be found.

 

Hmm..you wanted advice on how to troubleshoot but not willing to trouble shoot?

Look...bare wires are not a good sign, also unplugging the module doesn’t fix the fact that it sounds like a hack job to begin with. Remote start and immobilizer installation does require cutting certain wires and not just tapping onto them. If the connections are bad or are grounding by shifting while you are driving and touching metal, such as your statement about bare wires, this will cause issues as well. There are 3 wires that the module should have been attached to the immobilizer and they are transmit/receive/key sense. If those are touching each other or grounding, truck ain’t starting. There’s a chance a loose connection/grounding is causing the module to send a key code to the truck, meanwhile you are trying to start it with a different key with a different code, thus causing a conflict.

There are several wires in your ignition harness, they need to be powered a certain way in order for the truck to start. Once again, a hack job can cause 1 wire such as the one that should be getting 12 volts when the key is in the “on” and “start” position (ignition) in order for all Electronics to get power to start. These same wires provide power to your fuel pump and other electronics.

anyways, my recommendation to rip out the remote start still stands. I only installed car electronics, stereos, alarms, remote starts for like 10 years so what do I know.

Good luck

 

My 08 tundra won't start if I leave the key in the ignition for more than a week.

When it won't start because I did the above, I just pull the key out and insert it 180 degrees from the original insertion.

 

No, I 100% believe you. I have to acknowledge when stuff gets outside my range of expertise, and this may be it.

Still need to get Techstream on it when it’s having an episode, just to be sure. It still hasn’t acted up since right before the original post, and I monkeyed with a lot of those wires under the dash today.

We may just have to decide if we take the hit paying someone to fix it, or take the hit on sale value and let someone else deal with it.