K 1500 Suburban 4WD V8-5.3L VIN Z Flex Fuel (2003)
Shift Solenoid: Description and Operation
4L80-E/4L85-E
4L80-E/4L85-E
1-2 Shift Solenoid Valve
The 1-2 shift solenoid (SS) valve is a normally open exhaust valve that is attached to the valve body. The PCM controls the solenoid by grounding the
solenoid through an internal quad driver The 1-2 SS valve is ON in FIRST and FOURTH gear. When commanded ON, the 1-2 SS valve redirects fluid
to act on the 1-2 shift valve
There are two PCM related diagnostic trouble codes (DTCs) associated with the 1-2 SS valve: P0751 and P0753.
The PCM monitors the -2 SS circuit for an open or short to ground condition. If the PCM detects an open or short to ground condition, then DTC P0753
sets. If the PCM detects an incorrect gear ratio, then DTC P0751 sets. When DTC P0753 or P0751 sets, the PCM commands maximum line pressure,
freezes shift adapts from being updated. and inhibits 3-2 downshifts.
2-3 Shift Solenoid Valve
The 2-3 shift solenoid (SS) valve is a normally open exhaust valve that is attached to the valve body. The PCM controls the solenoid by grounding the
solenoid through an internal quad driver. The 2-3 SS valve is ON in THIRD and FOURTH gear. When commanded ON, the 2-3 SS valve redirects fluid
to act on the 2-3 shift valve.
There are two PCM related diagnostic trouble codes (DTCs) associated with the 2-3 SS valve: P0756 and P0758.
The PCM monitors the 2-3 SS circuit for an open or short to ground condition. If the PCM detects an open or short to ground condition, then DTC
P0758 sets. If the PCM detects an incorrect gear ratio, then DTC P0756 sets. When DTC P0758 or P0756 sets, the PCM commands maximum line
pressure, freezes shift adapts from being updated, and inhibits 3-2 downshifts.
