Bad ECM???

[Axekicker]

Very common , You do NOT need to replace ECM, I recovered many from this same problem, It requires someone that knows the work a round's of WItech.
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Current problem: Thursday 9-JAN-2020: Volt meter started running high (over 15 volts) recently. The truck was starting to get 'slow' turning-over in the mornings so I knew the battery's were being drained (or cooked). I took the truck back to the shop that rebuilt my motor last year and they said the passenger battery was 'cooked' but drivers was OK (these are new Costco/Interstate 1000CCA batteries). When the motor was rebuilt Nov. 2018, the shop installed ALL NEW BATTERY CABLES & ENDS so that takes them out of the equation. They sent the alternator out for testing and said it checked out OK. They checked the temp-sensor under the drivers battery and said it was OK. It's their 'best-guess'... the ECM is the 'cause' over the over-charge/over-voltage condition and they're telling me I need a new ECM. I'd like to have someone local, perform a 'diagnostic' on the ECM rather than send it all the way across the country to some unknown shop just to hear them say 'oh...yeah! It's shot and we'll send you a new one for $1,000.00+'

Recommendations? Should I have the shop pull the ECM and split the case and do a 'visual' for PC-board damage? (I'm a ham radio guy and regularly split radio cases looking for just that kind of damage to PC boards). IF no visual or 'olfactory' (can you smell the problem?) damage is observed or 'smelled'....then what? I'm not a fan of throwing parts at a problem as a substitute for real 'diagnostics'. I'm not convinced the ECM is the problem here. I'm thinking there's an issue that crops up 'under-load' which static testing won't find. How many times do they bench-test an alternator and pronounce it as "OK" and put it back in the vehicle only to find later that it malfunctions when it gets hot...under real-world loading/driving condtions?

TCDiesel: How can I find a local tech who knows how to do a WItech work-around?

Your thoughts guys?

 

[sag2]

It sounds like a bad crossover battery cable. Before I spent the money on a PCM if it is the cause I would convert to external regulator.

 

[Axekicker]

It sounds like a bad crossover battery cable. Before I spent the money on a PCM if it is the cause I would convert to external regulator.

Cross-over cable is new...all battery cables are new....ends are new....probably will do the external-reg conv.

 

[p-Bar]

Sag curious what you spec out for external regulator?

 

[Ozymandias]

Cross-over cable is new...all battery cables are new....ends are new....probably will do the external-reg conv.

You can NOT overcharge a single battery in this setup with a working wiring. It is not possible.
If your Pass Battery blew up several times then find the cause for it.
An external regulator won't solve this problem.

 

[cerberusiam]

Have you checked the charge voltage to see if it is actually high and the cross over cable really good?

 

[CharlesHoward]

New 05 ECM was $1299 at AutoComputerSpecialist.com with an above average "rating" Cheapest I saw online was $899

 

[p-Bar]

You better read this thread carefully
https://www.turbodieselregister.com...-indicators-lights.268165/page-2#post-2620577

 

[Axekicker]

UPDATE: Installed two new Caterpillar batteries and replaced one of the cable-heads which was loose & corroded...even though it was only 1 year old. The 1 year old Costco batteries were off-gassing which was corroding the battery terminals....which may have been part of the problem...and the shop-tech had over-tightened one of the battery clamps to the point that it was 'loose' and distorted...so I replaced it. So far so good. Truck runs great and no wide voltage fluctuations. I have a separate volt meter wired to each battery so I can monitor real-time at-the-battery voltage and as this photo shows, after engine warm up, it runs about 14.6 volts.

I'm going up into Utah Friday to pick up a trailer....we'll see how it goes.

 

[Axekicker]

So...I made the run from Las Vegas to Cedar City to pick up the trailer last Friday morning. Left at 3:30am and back home by 8:30am. That's 5 hours, 313 miles, 21.6 mpg for the trip (empty bumper-pull flat-bed 18' trailer, unloaded). I noticed that battery voltage increased as temps dropped. It was 50 degrees when I left Vegas and voltage was 14.6. When I hit Cedar it was 17 degrees and battery voltages were bouncing between 14.9 and 15.0. When I got back to warm-country batt voltages were back to 14.6 and holding steady. Bad battery terminal connections due to an over-torqued and damaged +connector was the likely culprit...not a bad ECM as the mechanic said. The Coscto batteries were also 'weak' per my load-test, so new Cat's and a new +terminal connector and I'm good-2-go.