CM 870 JAKE BRAKES

[yardie]

Hi Rawze I'm still trying to figure out what the problem is.
I confirmed it is the later style head jake brake set up for CM870 I have so its two solenoids as you had said.
The PSN, ESN and SSN all match up as the original which came with the original truck.
ESN : 79155395
ECM Serial number 26047914
Calibration software phase 06050302
ECM code AB10351.16
did all the troubleshooting steps as per quickserve for fault code 2368.
Checked the wring from ecm pin 31 and pin 11 to engine brake harness connector pin 1 and pin 5. all is well no open and no short. Checked resistance of both solenoids and both are reading within specs. Checked engine brake harness and no fault as well.
Checked and monitored on insite and verified all 3 levels of engine brake switch input when selected. (33%, 66%, 100%)
also checked and monitored engine brake output for all 3 levels but engine brake solenoid #2 signal which is engine brake output circuit 2 does not become active at any time. So only engine brake output circuit 3 becomes active when engine brake is requested. So according to the prints on quickserve only cylinders 4,5,6 are providing engine brakes all the time and nothing from 1,2,3

The strange thing is that after a few days driving i get an fault code 2368 which is for engine brake solenoid #3 signal. The fault becomes inactive but after a few days of driving the counts went up to 255 times.
i even checked at the solenoid itself and only solenoid #3 gets 12v. Solenoid #2 remains at 0V.
Solenoids #2 would fire up when a test 12 v was given and same for solenoid #3 so the solenoids are both good.

Now what could be the issue why solenoid #2 (cylinder 1,2,3) is not firing up?
The engine is not de-mandated to "my knowledge" and it still have the original VGT turbo on it.

there also two other codes
1. code 2349 active (112 counts) - egr valve control circuit open
2. code 2346 inactive (255 counts) - turbocharger turbine inlet temperature above normal range.
Could any of these faults contribute to weak jake brake issue or what could be the problem?