As vehicle speed increases and operating conditions become appropriate, the transmission control module (TCM) processes input signals from the automatic transmission input and output speed sensors, the throttle position sensor and other vehicle sensors to determine the precise moment to command ON the normally-low 26 pressure control solenoid and shift the transmission into Second gear. The manual valve remains in the Drive (D) position and line pressure continues to feed the drive fluid circuit.
26 Pressure Control (PC) Solenoid
The 26 PC solenoid is commanded ON, allowing actuator feed limit fluid to enter the PCS 26 clutch fluid circuit. PCS 26 clutch fluid is then routed through orifice #24 to the 2-6 clutch regulator valve.
2-6 Clutch Regulator Valve
PCS 26 clutch fluid, at the 2-6 clutch regulator valve, opposes 2-6 clutch regulator valve spring force and orificed 26 clutch fluid pressure to regulate drive fluid pressure into the 26 clutch circuit. 26 clutch fluid is then routed through orifice #22 to the 2-6 clutch assembly in the transmission case, and through orifice #4 to the spring end of the 2-6 clutch regulator valve.
2-6 Clutch
The 26 clutch fluid from the 2-6 clutch regulator valve is routed through the transmission case to the 2-6 clutch piston assembly. The 26 clutch fluid pressure moves the piston against 2-6 clutch spring force to apply the 2-6 clutch plates.
Accumulator
PCS 26 clutch fluid is also routed to an accumulator valve. The accumulator valve is used to dampen any pressure irregularities occurring in the PCS 26 clutch fluid circuit. This helps to control clutch apply fluid pressure and clutch apply feel.

Drive Range, Second Gear (Gen 1)
Drive Range, Sixth Gear (Gen 1)ABS Description and Operation
This vehicle is equipped with the MGH 60 Mando electronic stability control antilock
brake system. The electronic brake control module and the brake pressure modulator
are serviced separately. The brake pressure modulator uses a four circuit configuration
to control hydraulic press ...
Tires and Wheels Description and Operation (Tire Identification)
Identification
Accessory and warranty replacement must use TPC spec tires.
An outboard orientation stripe is added to the tread surface, with an
offset toward the outboard tire face.
All GM approved tires (Production, Service and Accessory) have a TPC
(Tire Performance C ...
Case Porosity Repair
Some external leaks are caused by case porosity in non-pressurized areas.
Thoroughly clean the area to be repaired with a cleaning
solvent. Air dry the area.
Warning: Epoxy adhesive may cause skin irritations and eye damage.
Read and follow all information on the container label a ...