F 250 4WD Super Duty V10-6.8L VIN Y (2006)
^ Correlation between engine speed and resistor values:
- The external voltage source that the aftermarket PTO system designer uses to command SEIC through the "PTO" or "PTO-Request" circuits
must be the same as that used by the PCM internally for predictable SEIC function. Reasoning is that a fully-charged vehicle battery fluctuates
with ambient temperature.
- The correlation will be better for diesel engines since the diesel engine SEIC system offers buffered PCM voltage and ground circuits to
complete the resistor circuits for engine speed, while the gas engine system forces the SEIC circuit installer to use chassis voltage and ground.
- If there is a high electrical demand on the chassis battery, such as from aftermarket inverters or generators, etc., the actual elevated idle engine
speed may vary with that demand for any given resistance in the SEIC circuit. More so for gas engine systems than diesel since gas engine uses
chassis battery voltage as a reference.
^ GAS Engine Only:
- Normal base engine calibration allows approximately +/-50 rpm fluctuation. If any factory vehicle accessories are used during SEIC, e.g. a/c,
defroster, etc., then that fluctuation may increase to approximately +/-1OO rpm or more.
- The sudden loss of aftermarket PTO hydraulic pressure during SEICIPTO operation, like a ruptured hose, may send SEIC engine speed to near
3000 rpm. It is recommended that a hydraulic pressure switch linked to SEIC/PTO be added to disable SEIC/PTO when a hose ruptures.
- Because of a service brake circuit characteristic at engine-start, invoking SEIC may cause the diagnostic error code FFG_BOO to get flagged
(recorded in the PCM). To avoid this, simply tap the service brake pedal sometime after engine-start and prior to invoking SEIC. Once the
code is set, SEIC may not be available until it is erased.
- Gas engines require a "change-of-state" at the PTO-Mode and PTO-Engage circuits whenever a disabler turns off SEIC (remove battery
voltage signal and re-apply).
- For aftermarket remote engine start-stop: a change-of-state is required to get SEIC to function again.
