Rick's Free Auto Repair Advice

Jeep won’t start

My Jeep won’t start

Several people have posted questions on help forums about what to do when their Jeep won’t start. Here are some of the top reasons. Since there are several Jeep models and different designs over the years, this is just a summary. If you want detailed information on YOUR system, buy a subscription to AlldataDIY or eautorepair.net from the links below

You turn the key and lights come on, but starter does not start cranking

Ignition Switch

Jeep is experiencing cracked/split ignition switch/lock cylinder

ignition switch, no start

Jeep ignition switch

related failures. In some cases a plastic tab breaks off the switch and allows it to flex/twist or move slightly. In others, the lock cylinder housing cracks. The switch moves enough to supply power to the lighting contacts, but not enough to power up the starter. Check the switch. If the lock cylinder housing is cracked, you’ll need a new steering column. Start checking the junk yards.

Linkage between lock cylinder and ignition switch

Linkage from lock cylinder to ignition switch breaks

Neutral safety switch

The PCM must see that the vehicle is in Park or Neutral. Some

neutral safety switch, transmission range selector

Neutral safety switch

of these safety switches are know failure points. The switch is located on top of the valve body and is called the transmission range selector (TRS). Try starting the vehicle in neutral rather than park. If that does it, the TRS is either out of adjustment or corroded. Plug the connector apart and look for green corrosion. If you find it, treat it with Stabilant 22

Security Light is on

There’s a problem with the SKIM security module

No Check Engine Light

The Check Engine Light should ALWAYS come on


Powertrain Control Module (PCM/ECM)

when you first turn the key. It’s doing a “bulb check.” If you’ve checked the bulb and it’s ok, you’ve got connection or PCM problems.


© 2012 Rick Muscoplat


Posted on by Rick Muscoplat

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