2015 Express 4500:
So this time it is the Antitheft. Drove the RV from CO to NC with no issues. Pulled in the driveway and shut it down. Went out an hour later and it will not crank. The theft light is on and when I turn the key to start, nothing... no crank. Acts like a dead battery. I've tried a few of the "fixes" from the web with no results. What causes this? Is there a fix I can implement at home or is having it flat bedded to the dealer my only option?

Gary

 

If you have a second working key, give it a try.

 

We have two keys… same results with both. Thinking I will head over to the dealer and pick up another one.

 

New key…same results. Is there a chance these symptoms could be related to something other than the antitheft? When I first put the key in without turning it, the antitheft indicator stays on after the other lights turn off.(first picture) when turning the key, all the lights go out except the engine symbol.

 

Anyone have suggestions on a diagnostic tool that would identify the cause and reset the Immobilizer?

Gary

 

Well, the antitheft was the symptom. The cause is yet to be determined. I found F22 blown! It is a 2amp fuse, replaced it, and the beast cranked and started! Now to find the short...

 

So, our recent fiasco was traced to a blown 2amp fuse i. The immobilizer circuit. My question is; has anyone “programmed” out this circuit?

 

Forget it. Just maintain your fuses. The fuse box should be the FIRST place you check when you have electrical problems.

 

Reviving this thread...The RV exhibited the same symptoms again yesterday. However, this time F22 was not blown! I pulled it and measured it with an ohm meter and re-installed...the engine started!! So I thought maybe I "fixed" it again. I decided to press on all the fuses and pull/reseat all the relays. After doing so, the engine would not crank. So I pulled F22 again and replaced it and the engine started. (As I noted in the past, the instrument cluster would quit intermittently shut off while underway. One of the fuses for it is next to the F22 fuse.) I'm beginning to suspect a fault fuse box under the seat and wonder if I should just replace it. Has anyone done this and can share their thoughts/experience?
Gary