This may have been asked before but my search didn’t turn up exactly what I’m experiencing.

2018 4Runner SR5 Premium, we purchased the truck used about a year and a half ago. When we first got it, the remote start worked with the factory Toyota key-remote. Now, when you use the remote, the truck will try to crank, but won’t start. And when you get in the truck to try to start it with the key, it still won’t start. We found that you have to jump the battery (using a jump box) to get it to start and run.

Any ideas? We’re just ready to trash the remote start…

Thanks for any feedback

This may be a dumb question, but did you have the battery tested?

The battery is only a few months old. The remote start quit working a couple of months after we bought the truck. The battery was replaced just a few months later.

is it a toyota OEM remote start or aftermarket?

To the best of my knowledge, it’s Toyota. It uses the Toyota 4Runner remote/key.

troubleshooting a remote start that doesn't work can be a nightmare. aftermarket kits also can use the fob, like accessorides. you can remove the remote starts with a lot of patience and care by cutting off the splices and covering any exposed wires. something like accessorides that is plug and play is very easy to remove

do you know where the control module is? it's probably tucked up behind the trim by the steering wheel as remote starts will often splice into wires back there as well as the ignition wires.

if it's an OEM remote start and you know it was installed by a dealer you can try and have them troubleshoot it. but if it was a DIY install you could be chasing for days to find the cause (assuming battery and other fobs are not the issue)

This sounds like an electrical gremlin. What, if any mods have you done, particularly anything involving any wiring or rewiring?

FWIW, the remote start control unit Toyota uses as a factory/port option often doesn't last. I went through several issues where remote start wouldn't work, but you could turn the key and it would start just fine. I ended up paying to remove the dead factory crap and then went to somewhere else and had them install a quality CompuStar system. I've had no issues since, and my only regret was not doing that when I bought the truck at the start.

Am I reading this right though? You need a jump-pack to start the truck normally (not remote) after the remote start attempt fails? I assume you don't need the jump pack normally to just start the truck? That doesn't sound like a fun issue to troubleshoot. My first thought is a vermin chewed wire related to the remote start control unit. Or possibly something with the immobilizer not getting proper power?