Seville STS V8-4.6L VIN 9 (1998)
Shift Solenoid: Description and Operation
1-2 AND 2-3 SHIFT SOLENOID VALVES
A shift solenoid valve is a two-port, feed-bled device consisting of a coil/plunger-ball assembly. The solenoid assembly works with an orifice to
pressurize the shift valve end chamber when voltage is applied to its coil. The controlled pressure then moves the shift valve against a spring causing a
shift to occur. When voltage is no longer applied, the chamber opens to exhaust and the opposite shift valve action occurs. Shift solenoids eliminate
the need for TV and governor pressures to control shift valve operation.
The 4T80-E transmission uses two shift solenoid valves: the 1-2 and 2-3, which are attached to the lower valve body.
Shift solenoid resistance should measure 19 - 24 ohms when measured at 20°C (68°F). Resistance should measure 24 - 31 ohms when measured at
100°C (212°F). Shift solenoid current flow should not exceed 0.75 amps. The shift solenoid valve should energize at a voltage of 7.5 volts or more
(measured across the terminals). The shift solenoid valve should de-energize when voltage is one volt or less.
IMPORTANT: If both solenoids lose power, only Second gear will result.