The ECM monitors the following criteria to make sure certain conditions are met.
• ABS (inactive)
• RPM (greater than 1200)
• APS (less than 5%)
• Idle validation
• EOT (greater than or equal to 60 °C [140 °C])
• Operator input switches (On/Off) (power selection– Low, Med, High)
If On is selected, and the preceding criteria is met, the engine brake will activate.
When the engine brake is activated, the ECM provides the power to activate the brake shut-off valve to allow
oil from the injector oil gallery to flow to the brake oil gallery. High oil pressure activates the brake actuator
pistons to open the exhaust valves.
During an ABS event, the engine brake is deactivated. The engine brake is activated once the ABS event is over.
The ECM removes the power source from the brake shut-off valve to deactivate the engine brake.
Residual brake gallery pressure initially bleeds from the actuator bore. When brake gallery pressure
bleeds down to 6895 kPa (1000 psi), the brake pressure relief valve opens, and oil drains back to sump.
