Cylinder Deactivation Inhibit Reasons
Listed below are the powertrain conditions that will inhibit V4 mode, while operating under light load driving conditions:
- Engine manifold vacuum low
- Brake booster vacuum pressure low
- Accelerator pedal position rate of increase too high, electronic throttle control
- Accelerator pedal position too high, electronic throttle control
- Ignition voltage out of range
- Engine oil pressure out of range
- Engine oil temperature out of range
- Engine RPM out of range
- Transmission gear incorrect
- Transmission range incorrect
- Transmission gear shift in progress
- All cylinders activated via scan tool output control
- Minimum time in V8 mode not met
- Maximum V4 mode time exceeded
- Engine oil aeration present
- Decel fuel cutoff active
- Fuel shut-off timer active
- Minimum heater temp low, HVAC system
- Reduced engine power active, electronic throttle control
- Brake torque management active
- Axle torque limiting active
- Engine metal over temperature protection active
- Catalytic converter over temperature protection active
- Piston protection active, knock detected
- Hot coolant mode active
- Engine over speed protection active
- Fault Active or Fault Pending-cylinder deactivation is disabled for the following faults:
- Brake Booster Vacuum Sensor
- Manifold Absolute Pressure Sensor
- Engine Oil Pressure Sensor
- Engine Coolant Temperature Sensor
- Vehicle Speed Sensor
- Crankshaft Position Sensor
- Engine Misfire Detected
- Cylinder Deactivation Solenoid Driver Circuit
The scan tool output control is used to deactivate half of the engine cylinders, V4 mode, by commanding all of the solenoids ON, or deactivate one cylinder switching to a V7 mode, by commanding ON one solenoid. Listed below are the powertrain conditions that will inhibit V4 mode, or V7 mode, with the engine running, while using the scan tool output control function:
- Engine speed out of range
- Manifold absolute pressure (MAP) sensor fault
- Accelerator pedal position too high, electronic throttle control
- Piston protection active, knock detected
- Engine oil temperature out of range
- Engine oil pressure out of range
- Engine oil aeration present
- Engine metal over temperature protection active
- Accelerator pedal position rate of increase too high, electronic throttle control
- Cylinder deactivation solenoid driver circuit fault
- Engine coolant temperature sensor fault
- Catalytic converter over temperature protection active
- Brake booster vacuum pressure low
- Brake Booster Vacuum Pressure Sensor Fault
- Axle torque limiting active
- Brake torque management active
- Vehicle speed sensor fault
- Engine coolant temperature too high
- Engine not running
- Vehicle speed not zero
- Engine coolant temperature low
- Reduced Engine Power Active, electronic throttle control
- Transmission gear incorrect
- Transmission range incorrect
- Ignition voltage out of range
- Maximum V4 mode time exceeded
Listed below are the powertrain conditions that will inhibit a cylinder deactivation solenoid from being energized, with the ignition ON and the engine OFF, while using the scan tool output control function:
- Engine speed not zero
- Vehicle speed not zero
- Transmission not in park or neutral
- Ignition voltage out of range
For the system description covering the hydraulic/mechanical system of cylinder deactivation, refer to Cylinder Deactivation (Active Fuel Management) System Description .