2005 Ram Cummins Code P1222

Hello,

I have code P1222 high return flow
I performed the return flow test and found a problem with the injectors. I replaced them all with new Bosh replacement along with new transfer tubes and new lines. Now the code comes on/off while driving on the freeway. I tested the pump and pressure relief valve and they pass the test. I don’t know what else to do. Has anyone encountered this problem?
Thank you

 

Was the vehicle updated to the latest software revision in the past?
They sorted out all kinds of software bugs through the years.

 

I took the truck in to the dealer in July 2022 for a ECM re flash that was supposed to fix the smog monitors not setting.

 

A day after the reflash I got the grid heater light on with 10 chimes and the rest is history. 3K into the truck that was running perfectly fine.

 

Verify what they flashed, my 03 didn't recognize the new injectors, tubes or FCA I installed until I was flashed to the latest updates for DRB III. I still had all my hanging idle symptoms with the new components until I got it flashed.

 

The reason the code started setting was the logic was included in the flash for the emissions monitor. It sets on a closed throttle decel when no fuel should be flowing into the cylinders. If the rail pressure does not maintain a certain level (it's different for all rail pressures) beyond the calculated internal leakage of the injectors it assumes a leak on the high pressure side. It takes several monitor events to set the light, chime, and code. If you have a way to monitor set and actual rail pressure you might be able to see it happening. First question is how did you check the injector return, and what was the result? Did you perform the test with a scan tool that raised the RPM and rail pressure, or just at idle? Engine hot or cold?

 

I performed the test at idle for one minute with tool 9012A engine got run for one minute and measure the injector return flow. No more than 180ml per minute
I got 50 ml after the injectors were replaced. mover 300 before the injector replacement.
also performed the return flow of the high pressure pump no more than 1000ml per minute at idle with the engine at operating temperature. I got 650 ml.
My OTC encore is not able to raise the RPM and fuel pressure.

 

I drove the truck for a second test drive to the local mountains and the code never came back. I have driven the truck now for more that 300 miles with no issues.

 

Update to the P code.
I drove the truck to Kernville this past week towing my 2 ft toy hauler and the truck ran great. conclusion= the injectors and tubes did the trick and the truck is fixed.