Specifications

87
Data Parameters Transmission Parameters
within eight cells or memory bocks. Each memory block contains specific input values
(comparisons) as well as adaptive learning output commands.
A transmission is most susceptible to damage when a shift is in process. Typically, transmission
shifts take approximately 0.4 to 1.35 seconds to complete. The time when a component is not
fully released or fully applied is called “shift overlap.” Shift overlap varies with operating
parameters and transmission condition. High torque engines can cause severe damage to
clutches during shift overlap. Therefore, during the shift it is beneficial to limit torque during shifts.
As the electronic transmission controller (ETC) receives various input, such as, gear ratio, shift
solenoid position, TPS, and RPM, it can determine when a shift is about to occur. Currently, the
technique calls for a momentary reduction (or retard) of spark advance. The spark retard can be
as much as 57 crankshaft degrees, delaying torque output up to as much as 20 milliseconds.
This allows the shift to occur with reduced engine torque during the points of the shift overlap,
thus reducing the strain on the clutches.
Adaptive torque memory updating and storage will continue unless battery power is lost to the
ETC. If battery power is lost, the ETC will default to the base settings.
ALTITUDE FACTOR (%)
Range: _________________________________________________________ 0 to 100%
Used on EGS system. This parameter displays the altitude correction factor as a percentage.
The electronic transmission controller (ETC) uses this information to adjust line pressures
according to changes in altitude, which translates into an altitude factor. As elevation changes
occur, air density changes, as does engine torque output. Altitude factor enables shift pressure
adjustment to compensate for elevation changes.
CNTRL VALVE CURRENT-MP(nominal)(ma)
CNTRL VALVE CURRENT-MP(current)(ma)
CNTRL VALVE CURRENT-SP(nominal)(ma)
CNTRL VALVE CURRENT-SP(current)(ma)
Range: __________________________________________________________ variable
Used on EGS systems. This parameter displays modulating and shift pressure (MP and SP,
respectively). The electronic transmission controller (ETC) converts a variable current into a
proportional hydraulic pressure.
“Nominal” in the name represents the calculated value stored in the transmission control module.
“Current” in the name represents the actual or live milliampere reading.
Modulating pressure is adjusted at the regulating solenoid valve. The height of the modulating
pressure is dependent on engine load. It acts on the working pressure control valve and the
pressure overlap control valves. Modulating pressure influences the height of the working
pressure, which determines, together with the shift pressure, the regulated pressure at the
pressure overlap control valve.
The shift pressure regulating valve and shift pressure control valve determines the maximum
shift pressure. Additional pressure from clutch K2 acts on the annular surface of the shift
pressure control valve and as a result, the shift pressure in 2nd gear is reduced.
The purpose is to regulate the pressure in the shift element to be engaged during the shifting
phase. This determines, together with the modulating pressure, the pressure overlap control
valve regulated pressure at the disengaging shift element. Also, modulating and shift pressure
initialize working pressure for the 2nd gear limp-home mode (electrical fail safe).
Normal range for both shift and modulating control valve current at idle, warm engine in Park
varies from 500 to 800 mA.