No start after highway driving

[Stuttercat]

Hello!! I have a 2018 Jeep JK - we have been having issues on and off since purchasing it. I will start it, drive it on the highway about 10 minutes, and then turn it off. After turning it off - it will not turn back on for about 30-50 minutes. We got a brand new battery, no change. We changed the CPS - thought it was solved but problem reappeared the next day.

Trans temp usually around 160F Oil pressure about 21 psi Coolant temp around 206F but have seen it up to 227F

Any guesses as to a direction to turn? Not sure if it’s a computer or radiator issue. Reading through forums just lead to dead ends - no one actually stating fixes the thread just eventually dies.

 

[tJKrider]

Hello!! I have a 2018 Jeep JK - we have been having issues on and off since purchasing it. I will start it, drive it on the highway about 10 minutes, and then turn it off. After turning it off - it will not turn back on for about 30-50 minutes. We got a brand new battery, no change. We changed the CPS - thought it was solved but problem reappeared the next day.

Trans temp usually around 160F Oil pressure about 21 psi Coolant temp around 206F but have seen it up to 227F

Any guesses as to a direction to turn? Not sure if it’s a computer or radiator issue. Reading through forums just lead to dead ends - no one actually stating fixes the thread just eventually dies.

My guess is junk factory clamps not fully seated and causing intermittent starting issues. Ask me how I know!

Temp fix - loosen and tap them down to fully seat them
Permanent fix - replacement

 

[JeepJeezy]

Hello!! I have a 2018 Jeep JK - we have been having issues on and off since purchasing it. I will start it, drive it on the highway about 10 minutes, and then turn it off. After turning it off - it will not turn back on for about 30-50 minutes. We got a brand new battery, no change. We changed the CPS - thought it was solved but problem reappeared the next day.

Trans temp usually around 160F Oil pressure about 21 psi Coolant temp around 206F but have seen it up to 227F

Any guesses as to a direction to turn? Not sure if it’s a computer or radiator issue. Reading through forums just lead to dead ends - no one actually stating fixes the thread just eventually dies.

My wife's friend has an 18 JK but found out there are some JL features installed too. Her JK has the auxiliary start battery that the JL came with. She was having starting issues. The dealer installed a new battery, programmed new fobs, flashed the security, and it still had the same problem. The one tech thought her Jeep was a JL and found the aux battery. Replaced it and the Jeep started with no issues. Maybe worth checking?

 

[72c10]

Hello!! I have a 2018 Jeep JK - we have been having issues on and off since purchasing it. I will start it, drive it on the highway about 10 minutes, and then turn it off. After turning it off - it will not turn back on for about 30-50 minutes. We got a brand new battery, no change. We changed the CPS - thought it was solved but problem reappeared the next day.

Trans temp usually around 160F Oil pressure about 21 psi Coolant temp around 206F but have seen it up to 227F

Any guesses as to a direction to turn? Not sure if it’s a computer or radiator issue. Reading through forums just lead to dead ends - no one actually stating fixes the thread just eventually dies.

Had that issue on an Escalade before, narrowed it down to a negative battery cable that looked just fine - even when my mechanic and I cut it up and inspected the inside. Might be worth a shot.

 

[Stuttercat]

We checked battery cables, fuses, replaced the starter - problem still persists. Will be trying the starter relay and having the battery connectors replaced to see how that goes.

 

[WSS]

My JKU did the same thing recently, let it cool off and it will start. But it did get worse. It was the TIPM. To be clear, do you get a "crank, no start" or a "no crank"?

If you jump relay K3, you should get a "crank and start". If it is just a "crank, no start", it is likely a failing TIPM,