Powertrain Control Software

Auto Start Stop 

The auto start stop system helps reduce fuel consumption and decrease emissions by automatically shutting down the engine when the vehicle stops and the engine is idling, usually within 1500 ms (1.5 seconds). To initiate the auto start stop operation, the vehicle gear selector must be in DRIVE when the vehicle comes to a stop and the brake pedal must be fully applied. The engine automatically restarts when the brake pedal is released, usually within 200 ms (0.5 seconds), or when a vehicle system requires a restart, for example to recharge the battery or to maintain interior comfort settings.

The auto start stop system is defaulted to an ON state when the engine is started. To switch the auto start stop system OFF, press the auto start stop switch located on the center console. To turn the auto start stop system ON, press the auto start stop switch again. The auto start stop system can only be deactivated during the current ignition cycle.

The IPC auto start stop indicator illuminates when an auto start stop system inhibit or disable condition is present. During normal operation the auto start stop system may not stop the engine under the following conditions:

• The A/C, heat or defrost settings are ON
• The rear defroster is ON
• The battery has a low state of charge or is below 5deg.C (41deg.F) or above 60deg.C (140deg.F)
• The maximum engine off time is exceeded
• The engine operating temperature is less than 60deg.C (140deg.F)
• The gear selector is in the PARK, REVERSE, NEUTRAL or SECOND GEAR position
• The steering wheel is turned rapidly or is at a sharp angle
• Initial vehicle speed of greater than 4 km/h (2.5 MPH) and less than 2 seconds has elapsed
• The vehicle is on a steep road grade
• Elevation is above 10, 000 feet (3, 048 meters) approximately
• The CPP sensor indicates the clutch pedal is fully released

Any of the following conditions may result in an automatic restart of the engine:

• The blower fan speed is increased or the climate control temperature is changed
• An electrical accessory is turned ON or plugged in
• Incorrect brake vacuum
• The auto start stop switch is pressed to disable the system while the engine is stopped

Cold Idle Kicker 

The cold idle kicker strategy provides an increase in idle speed during cold engine warm up. The PCM uses the ECT sensor and transmission position as primary inputs, and in certain conditions the PCM uses the ambient air temperature input to adjust the cold idle RPM up to a maximum of 1, 175 RPM.

Diesel Engine Power Monitor 

The diesel engine power monitor strategy resides in the PCM. The function of the diesel engine power monitor is to check the engine operation for unwanted fuel injections without a driver demand. During the diesel engine power monitor the PCM checks the commanded fuel injections and engine speed.

Engine Shutdown Timer 

Vehicles equipped with the engine shutdown timer have an instrument panel cluster message and an audible alert that notifies the driver 30 seconds prior to engine shutdown. When the engine shutdown occurs, the PCM broadcasts a shutdown message to all the vehicle modules. One minute after the engine shutdown occurs, the body control module (BCM) (F-650 / F-750) or the circuit deactivation ignition module (CDIM) (all others) electrically changes the ignition state to OFF and the vehicle goes into the normal delay accessory mode.

Engine shutdown occurs under the following conditions: Engine shutdown occurs under the following conditions:

• Vehicle speed below 1.6 km/h (1 mph)Vehicle speed below 1.6 km/h (1 mph)
• Engine coolant temperature is greater than 15deg.C (60deg.F)Engine coolant temperature is greater than 15deg.C (60deg.F)
• Transmission in the PARK or NEUTRAL position Transmission in the PARK or NEUTRAL position
• Engine shutdown occurs in 5 minutes with the parking brake applied.
• Engine shutdown occurs in 15 minutes without the parking brake applied
• The engine shutdown time may be increased in regeneration mode or scan tool mode (60 minutes maximum)
• Brake or accelerator pedal application in the 30 second window resets the engine shutdown timer
• Power take off (PTO) or auxiliary idle control system not active

Fuel Balancing And Control 

Fuel balancing and control is an algorithm designed to reduce differences in injected fuel quantity from cylinder to cylinder. The increase in crankshaft speed due to individual cylinder combustion events is measured. The amount of fuel injected to each cylinder is then adjusted up or down to minimize the difference in increase in crankshaft speed from cylinder to cylinder. Fuel balancing and control operates in closed loop control in an engine speed range of 500 to 2800 RPM and a commanded injection quantity of 3.5 to 75 mg per stroke.

Fuel Mass Observer 

The fuel mass observer is an algorithm used to detect deviations in performance of all fuel injectors from nominal. The oxygen percentage as measured by the nitrogen oxides bank 1, sensor 2 (NOx12) is compared to a modeled oxygen percentage based upon the current fuel, boost, and EGR settings. The deviation between the measured and modeled oxygen percentage is expressed in terms of the error in fueling required to explain the deviation. This calculated error in fueling is then divided by the current requested fueling level to generate a ratio of percentage error in fueling. This fueling ratio is then filtered over time. If the filtered error in fueling ratio exceeds minimum or maximum limits, then a DTC is set.