2011 Jeep Liberty - Intermittent no start command.

[Fordiesel69]

Have a friend with a 2011 jeep liberty with the 3.7L engine. Starting about a year ago shortly after and engine replacement you will turn the key and the starter does not energize. It is not an IGN SW / KEY FOB / or security issue. There is no aftermarket accessories installed to get in the way.

With the old TIPM module, you could turn it to start position, get nothing, and then at times you can tap on the TIPM module and it would then start. Like the start command was still in the TIPM but not outputting.

We installed a new reman TIPM from a very legit company, and the problem vanished for about a week, and has now come back. It is so intermittent that by the time you get the lid off the TIPM and get your meter connected it will start every time.

I had explored the option of sourcing a male pin from the tipm connections, and by eye and feel insert that pin into each connector to test the friction fit.

Any ideas where to begin?

 

[tnt_motorsports]

it might be worth taking to a Jeep dealer for diagnostics. The fee to do that is probably way less of a headache than what you are going through. My son had a 2009 GC that had an intermittent start issue. It was caused by a break in the engine harness along the frame beside the engine. The dealer sent a nice little video explaining this situation. They repaired the harness and the issue went away for good.

Just my $0.02

 

[Fordiesel69]

Yep been there and done that. Thousands of dollars worth of guesses. We do not have electrical experts in our area. They replaced the security module and some pickup sensor and the ignition switch. We replaced the TIPM and the suspect aftermarket starter.

Im curious if this would work. Becuase when you turn the key you can hear some relays in the TIPM operate, that tells me the problem is after the TIPM. Could we wire a push button to activate the starter solenoid after you turn the key for those times it wont start.

 

[MattPersman]

You can just energize the relay on the tipm to see if it’s control or output side. Could also wire a bulb on the output side of the tipm to the starter solenoid and see if it lights up when you crank at the key cylinder

Definitely could be a pin fitment issue on the wiring

Just need to do some more diag it’s a pretty basic setup

 

[zrxkawboy]

With the old TIPM module, you could turn it to start position, get nothing, and then at times you can tap on the TIPM module and it would then start. Like the start command was still in the TIPM but not outputting.

That kind of sounds like a relay sticking open until you tap on it.

 

[Fordiesel69]

The problem is when yuou attempt to diag, everything works perfect.

Eric O and Pine Hollow seem to always have it act up so they can pinpoint the exact cause.

 

[mk378]

shortly after and engine replacement

That's a clue to go over the starter itself, and the wiring on the engine since all that would have been disturbed to R&R engine. And always consider the #1 cause of intermittent no crank-- loose connections on the battery.

If you can always make it start with a rap on the TIPM module, you likely have a defective rebuild.

 

[Fordiesel69]

1.) We replaced the starter again as it was under warranty. No change. Wires and connections on starter look great and were cleaned.
2.) Unless we unwrap the entire engine harness, no way to know. But I do agree somewhat. This is not really an option we can explore as the labor is too much to do just a visual inspection.
3.) The factory as built TIPM, was replaced by the garage that did the engine. They got a used TIPM. We replaced TIPM#2 with a reman from a legit website with actual phone support. I would not think all 3 TIPMs would do the same thing.
4.) Battery was replaced and with headlights on, we are not loosing power at all. Dash, lights etc are all still active when this happens.

We do have a 2012 jeep liberty that we could in theory borrow a 4th tipm out of but it has never had a single electrical fault and we are hesitant it will work without reprogramming. We are also not interested in creating a problem where one does not yet exisit for our friend who owns it.

 

[mk378]

You need an easy way to tell if voltage is leaving the TIPM on the starter wire when you try to start but it doesn't. This should be somewhat permanently installed so you don't disturb the TIPM or the wiring during the test.