Inconsistant cranking on 6.7L

[BobTaylor]

I posted a couple of incidents on this in another thread, but since it has become such a goat roping, I thought I'd start a new thread in case it may help someone else.

I started having no crank incidents about a week ago and took my 3500 dually into the dealer and he diagnosed it as a bad WCM. Since they were on back order it took a full week to get one. (Service tech says they have had to replace a bunch of them). Starting got less and less frequent and I tried all the suggestions about the IOD fuse and battery cables that I could find to no avail. Finally got it started about 11:15 this morning after 25+ attempts today, (setting off the alarm seems to be of some help) and called the dealer and told him I was afraid to shut off. He said WCM was in and "bring 'er down. " They gave me a PT Cruiser rental to drive while they worked on it. In a little less than 3 hours, they called to say it was ready.

Guess what? The WCM did NOT correct the problem. Couldn't even get it off the lot. They are going to call STAR in the morning and they ordered a TIPM to see if that could be the problem.

I'll keep this thread updated so that others can see what's happening.

 

[Bob4x4]

I have had some new wcms that were bad right off the shelf... ... .....



Bob

 

[pwr2tow]

Almost ashamed to ask, whats a wcm

 

[BobTaylor]

Almost ashamed to ask, whats a wcm

Sorry, Wireless Control Module. As best I can tell, this controls all the remote keyless entry stuff as well as the no start feature of bogus keys. In my case, the key would do everything except start the truck. No crank at all, like it was locked out.

 

[BobTaylor]

I have had some new wcms that were bad right off the shelf... ... .....



Bob

How did you determine that? Just no fix? The dealer tech said that my problem didn't throw any codes.

 

[Bob4x4]

How did you determine that? Just no fix? The dealer tech said that my problem didn't throw any codes.

Not fully functional after programming.



Bob

 

[courierdog]

This may or may not be related. Since new I have noticed I can have a difficult start. My work around is to wait, patience is not one of my strong points, until the ABS light goes out then and only then start. IF I follow this procedure I never have a failure to start the first time. my reasoning on this is the new ECM has to think about everything before it allows fuel to flow and allow the firing of the engine. JMO
Let me know if it works for you.

 

[BobTaylor]

This may or may not be related. Since new I have noticed I can have a difficult start. My work around is to wait, patience is not one of my strong points, until the ABS light goes out then and only then start. IF I follow this procedure I never have a failure to start the first time. my reasoning on this is the new ECM has to think about everything before it allows fuel to flow and allow the firing of the engine. JMO

Let me know if it works for you.

No mine won't crank. Maybe all day long. Lots of waits lots of tries.

 

[BobTaylor]

Well, I'll give an end of the week update. The local dealer ordered another WCM after determining that the TIPM was not the problem. The new WCM did not fix, so the Chrysler Area Manager was contacted and he had the truck towed to a large dealer in Memphis that has the big-time diagnostic equipment to see if they could find the problem. They have provided me with a rental car, although you can't do much with a PT Cruiser. I sure can't pull my 5er anywhere.



Hopes are high for a Monday return of a running truck.

 

[BobTaylor]

No joy for Monday. I talked to the Memphis dealer and they are "working on it. " Serviceman has determined that it is an electrical problem, but no diagnosis so far. Must say that the dealer service tech that I spoke to was very accommodating and sympathetic to my problem.

 

[FATCAT]

Please ... NO ABBREAVIATIONS! I have no idea what you are talking about: WCM, IOD, TIPM??????



Also, what year is your truck? What Transmission?

 

[Bob4x4]

Wireless Control Module,Tottaly Integrated Power Module,Ignition Off Draw

 

[BobTaylor]

Please ... NO ABBREAVIATIONS! I have no idea what you are talking about: WCM, IOD, TIPM??????

Also, what year is your truck? What Transmission?

See my updated signature. I had the info in the Control Panel, but didn't get it into the signature.

The Memphis dealer advised me today that they have decided that the TIPM is indeed bad and have ordered another which won't be here until Thursday. I told him that the first dealer had changed that module with no cure, but they are going ahead thinking that maybe the first replacement was defective. I'm growing more and more suspicious that they have no idea what they are doing.

 

[BobTaylor]

Well here it is Friday and still no truck. I couldn't get any info from the Memphis dealer so I got the number for the Chrysler Area Manager. He was very nice and asked that I give him 'til Monday to try to sort it all out. He is the person who had the truck transferred to the Memphis dealer to begin with. What he told me was, "We'll either fix your truck or get you into a new one. " No dates were mentioned, however.

I hope this is all true, but I won't hold my breath.

 

[HBarlow]

Bob,



It is not clear to me what you meant when you said "won't crank. " Some folks use that phrase when they mean the rotating assembly will spin with the starter motor but the engine will not actually start... ..... others use that phrase when they mean the rotating assembly will not even spin when the key is switched to the start position.

 

[BobTaylor]

When I say "won't crank," I mean that the starter does not engage. It's as though the battery is completely dead, but it's not. In a lesser engineered system, I'd suspect the starter solenoid or the ignition switch, but these days that doesn't "compute. "

 

[HBarlow]

When I say "won't crank," I mean that the starter does not engage. It's as though the battery is completely dead, but it's not. In a lesser engineered system, I'd suspect the starter solenoid or the ignition switch, but these days that doesn't "compute. "

I agree. That sounds more like a bad connection somewhere. I assume your battery post connections are tight and nothing else has been removed and reinstalled for an accessory add. It sounds like you might have a defective ignition/start switch although I've never heard of anyone with that problem.

 

[BobTaylor]

Chrysler Area Manager called today to say that the dealer has found the problem. His story is that there is an intermittent in one of the wiring harnesses and they are looking for the particular conductor that is the culprit. I don't have a good feeling about their diagnosis, though. I've been in the electrical business for 40 years and I never saw an intermittent in a conductor that would clear itself with no outside aid. My truck would not start and sometimes just trying a few more times and it would start. No movement of anything but the ignition switch.

We'll see. The AM is to be at the dealership all day tomorrow and he promises me a call in the morning.

 

[HBarlow]

I'm a little less than confident of that diagnosis also but good luck, maybe that'll fix it.

 

[BobTaylor]

Well, it's Tuesday night and I finally have the truck back. I didn't get any paperwork from the dealer since they delivered it to the first dealer for me to pick up, but I intend to ask for it for a paper trail. The truck has started every time, so far. They still say that it was a bared conductor somewhere. I hope this is the end of it. I sure would hate for this to recur somewhere in Montana or Wyoming while I's dragging my 5er and out of cellphone range.