p202 and p2146 2005

[RWeatherbee]

I have read the other post in this area and not sure if the problem is in my ecm or not. Truck has only 58000 miles and is stock except for the muffler. I have checked all the resistances and injector #'s 1, 3, 4, 5 and 6 all read .5 ohms. #2 however reads .7 ohms. I have measured continuity from the ecm connector all the way through the solenoid and back to the connector and still have only .7 ohms. The truck did lose power and the light came on. The fact that number two reads higher than others but below the 1 ohm cut off makes me believe the ecm is at fault. I was wondering if anybody else has experienced this problem with injectors that are within tolerance required but still bad.

 

[AllianceDiesel]

Dont jump to the ecm. My dads pickup kicked a code for #1 injector and would clear once the engine cooled. So once the injector warmed the solenoid would get high resistance. Also seen one other pickup do the same thing.

 

[cerberusiam]

The .7 is high on that injector, assuming that is the code that is showing when it fails. The one you posted is incomplete.

Actual ohms should be .1 to .2 if you have a sensitive enough meter so a .7 is an indicator the solenoid is likely failing when it gets warm. You didn't post year and that is rather important as certain years were more susceptible to low mileage issues. Posting info on your truck will make it alot easier to troubleshoot with limited info.

 

[RWeatherbee]

the truck is a 2005. the meter is a $200 fluke digital so I feel it is fairly accurate.

I will run the truck till it reaches temperature and the measure the resistance to see if it changes. the ecm is the last thing on my list.. thanks for the input

 

[AllianceDiesel]

Actually chrysler says anything between .1 and 1 ohm is in spec

 

[cerberusiam]

the truck is a 2005. the meter is a $200 fluke digital so I feel it is fairly accurate.

A +/- .5 is standard for a $50 meter. A good meter will read to +/- .1 ohms. The .7 anomaly is a place to start.

Actually chrysler says anything between .1 and 1 ohm is in spec

Chrysler tech doesn't have a clue what the spec is or even how to interpret it. They made up their own interpretation becasue Bosch specs were too tight and it was costing corpoarate money on replacements. When a dealer pronounces it in spec per STAR thne you know you have a bad unit.

 

[RWeatherbee]

I cleaned and checked connectors now I will see if the problem comes back. It was a one time event so far but will put some miles on it locally before making any out of town trips. The out of town trips will not occur for at least two months. If the problem comes back I will return to the post and add the results.. thanks for the input

 

[sag2]

Cummins ECM's generally do not fail and should be the very last thing you would want to try. Swap the injector to another cylinder and see if it follows. Most of the failures are the valve cover gasket.

 

[RWeatherbee]

My wiring doesn't include the valve cover, I'm not sure that was one of Cummins/Chrysler best designs. I was going to try the swap on the injectors when I got another chance to work on the truck so thanks for the suggestion. I love spring just not all the work that goes with it. In hindsight (the great mechanic) it would probably be a good idea to take the injector resistance measurement when I bought the truck for a baseline and then at some interval of mileage to see how they are changing. The #2 injector may have been at .7 ohms for a long time or may have just increased in resistance. If one had a plug from a wrecked dodge that would mate with the injector cable just before it goes in the valve cover you could make a easy test connector for quick measurements.