Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM.
Possible causes:
1)Open circuit in the engine harness, brake harness, or engine brake solenoids 2)Short to voltage source in the engine harness. 3)Malfunctioning ECM.
Possible repairs:
1)Replace the engine brake solenoid. 2)Replace the ECM. 3)Repair or replace the engine harness.