Engine Stalls / Won’t Start?

[daytona701]

I have a 2007.5 6.7L Cummins was driving, the engine stalled, and the truck ran fine.

Red flashes on the dash and check engine light with no DTC with Harbor Freight scanner.

The crankshaft position sensor was damaged, so I replaced it.

Batteries are two years old at 12.68 volts, and the scanner says ECM sees 12.4 volts.

Key to start, nothing happens.

Plugged in Smarty Jr, which has been on truck for 10 years, gets communication errors 121, 122, and 116.

Smarty expert thinks the ECM is bad.

I am trying to figure out how to confirm whether ECM needs repair or replacement.

I don’t want to lose tune if possible. Can anyone on this site give advice?

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[AK Bob]

I have a 2007.5 6.7L Cummins was driving, the engine stalled, and the truck ran fine.

Red flashes on the dash and check engine light with no DTC with Harbor Freight scanner.

The crankshaft position sensor was damaged, so I replaced it.

Batteries are two years old at 12.68 volts, and the scanner says ECM sees 12.4 volts.

Key to start, nothing happens.

Plugged in Smarty Jr, which has been on truck for 10 years, gets communication errors 121, 122, and 116.

Smarty expert thinks the ECM is bad.

I am trying to figure out how to confirm whether ECM needs repair or replacement.

I don’t want to lose tune if possible. Can anyone on this site give advice?

Before replacing the ECM, I would check a wiring diagram and verify all the power and ground inputs at the ECM.

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[AK Bob]

I have a 2007.5 6.7L Cummins was driving, the engine stalled, and the truck ran fine.

Red flashes on the dash and check engine light with no DTC with Harbor Freight scanner.

The crankshaft position sensor was damaged, so I replaced it.

Batteries are two years old at 12.68 volts, and the scanner says ECM sees 12.4 volts.

Key to start, nothing happens.

Plugged in Smarty Jr, which has been on truck for 10 years, gets communication errors 121, 122, and 116.

Smarty expert thinks the ECM is bad.

I am trying to figure out how to confirm whether ECM needs repair or replacement.

I don’t want to lose tune if possible. Can anyone on this site give advice?

Any update?

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[daytona701]

No update yet.

I got the factory service manual on cd and will study it.

The truck is parked in front of my shop.

Keep thinking that the crankshaft position sensor may have something to do with the problem.

The sensor looks like it was held against a grinder wheel at a 45-degree angle to the face.

I can’t find what caused the damage.

I will put the truck on the lift and closely check the wiring grounds and connections.

The truck had been running fine before the engine abruptly stalled.

I wondered if anyone has installed a 12 valve in a later model truck.

It’d be good to run with no electronics.

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[AK Bob]

No update yet.

I got the factory service manual on cd and will study it.

The truck is parked in front of my shop.

Keep thinking that the crankshaft position sensor may have something to do with the problem.

The sensor looks like it was held against a grinder wheel at a 45-degree angle to the face.

I can’t find what caused the damage.

I will put the truck on the lift and closely check the wiring grounds and connections.

The truck had been running fine before the engine abruptly stalled.

I wondered if anyone has installed a 12 valve in a later model truck.

It’d be good to run with no electronics.

Thanks for the update.

It sounds like you are making progress.

Do you see any RPM readings when cranking?

Hopefully, someone will reply to your 12 valve question.

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[daytona701]

2007.5 Dodge RAM 2500 6.7L auto.

Ok, I have some questions.

What's the computer mounted on the driver's side of the engine?

What's the computer mounted on the passenger side of the firewall called?

What computer has the flash program?

What computer is the can bus located in?

I was hoping not to have to learn how the electronics work on this truck.

I was happy to drive and maintain it, but if I'm going to keep it to the million-mile mark, I have to learn how it works.

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[AK Bob]

2007.5 Dodge RAM 2500 6.7L auto.

Ok, I have some questions.

What's the computer mounted on the driver's side of the engine?

What's the computer mounted on the passenger side of the firewall called?

What computer has the flash program?

What computer is the can bus located in?

I was hoping not to have to learn how the electronics work on this truck.

I was happy to drive and maintain it, but if I'm going to keep it to the million-mile mark, I have to learn how it works.

If you want to learn more about your truck, this 8 part video series on YouTube is well worth the time.

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[daytona701]

Thanks for the link.

It’s fantastic the complexity of the electronics.

A significant investment is needed to have a stimulator, power source, code reader, and an oscilloscope to check the modules.

I sent my ecm off to get repaired still not 100% sure it’s the problem.

I need to find out if the the ecm can be flashed once I get it back.

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[daytona701]

I got the repaired ecm back and installed it on the truck.

Now truck starts for 3 seconds then shuts off.

The security light on the dash blinks continuously when the key is in position.

I’ve read before on a 2005 Jeep Liberty that I have it’s the skim module that doesn’t recognize the key and kills the engine.

Harbor Freight code reader set on vehicle identification says vin# n/a.

Tuner code reader says “wrong vin” and key/skim not matched.

ECU repairman says vin can be written to ecm but won’t tell me the equipment needed or how it’s done.

ECU repairman says to send the unit back for reload of the program, and if that doesn’t work, then need a new computer.

The local locksmith said to turn the key on for an hour to mate the key to skim and see if that works.

Another option is to trailer the truck to a locksmith and have the key programmed to the truck.

The batteries have 12.54 volts, and the key is on for 1 hour as per the locksmith.

I’m wondering if I should reload the ecm program that was running when the computer initially stopped working?

That’s the question.

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[AK Bob]

I got the repaired ecm back and installed it on the truck.

Now truck starts for 3 seconds then shuts off.

The security light on the dash blinks continuously when the key is in position.

I’ve read before on a 2005 Jeep Liberty that I have it’s the skim module that doesn’t recognize the key and kills the engine.

Harbor Freight code reader set on vehicle identification says vin# n/a.

Tuner code reader says “wrong vin” and key/skim not matched.

ECU repairman says vin can be written to ecm but won’t tell me the equipment needed or how it’s done.

ECU repairman says to send the unit back for reload of the program, and if that doesn’t work, then need a new computer.

The local locksmith said to turn the key on for an hour to mate the key to skim and see if that works.

Another option is to trailer the truck to a locksmith and have the key programmed to the truck.

The batteries have 12.54 volts, and the key is on for 1 hour as per the locksmith.

I’m wondering if I should reload the ecm program that was running when the computer initially stopped working?

That’s the question.

It sounds like your VIN is no longer in the ECU.

I am guessing you sent your original ECU to the repair shop, and they repaired and reprogramed it but didn’t write in your VIN.

I would check with the locksmith to see if he has the capability of writing the VIN to the ECU.

Do not load your previous tunes to your ECU until you get the VIN and keys sorted.

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