Description And Operation
DESCRIPTION
| 1 - M6 Valve Body Bolt Hole |
| 8 - Solenoid C |
| 2 - M5 Valve Body to Solenoid Body Bolt Hole |
| 9 - Torque Converter Clutch (TCC) Solenoid |
| 3 - Wiring Harness for Park Release Solenoid |
| 10 - Line Pressure Solenoid |
| 4 - Solenoid A |
| 11 - Park Release Solenoid |
| 5 - Solenoid B |
| 12 - High Impulse Solenoid (HIS) Wire Harness Connector |
| 6 - Solenoid D |
| 13 - Output Shaft Speed (OSS) Sensor |
| 7 - Solenoid E |
| 14 - Park Hold Solenoid |
The solenoids are integrated into the Transmission Control Module Assembly (TCMA) of the 8HP transmission and are not replaceable individually.
OPERATION
The Transmission Control Module (TCM), or Transmission Control Module Assembly (TCMA) is extremely sensitive to Electrostatic Discharge (ESD). Always use a ground strap and follow the ESD guidelines in ELECTROSTATIC DISCHARGE (ESD) SENSITIVE DEVICES. Failure to follow these instructions may result in damage to the TCM/TCMA.
The TCM will actuate the valves via solenoids based on the position of the shifter, transmission fluid temperature, engine operating conditions, traction conditions, and driver demands. During a shift, the TCM will actuate the solenoids to match the gear ranges to the optimal torque range of the engine based on the position of the accelerator pedal, shifter, and vehicle speed as determined by the Powertrain Control Module (PCM) based on signals from the Input Speed Sensor (ISS), Output Speed Sensor (OSS) and Antilock Brake System (ABS) module.
Solenoids
The EDS solenoids are identified by two distinct colors to help differentiate their characteristics and function:
There are two types of EDS solenoids designed for regulating pressure:
- The White/Orange EDS solenoids have a rising characteristic curve (there is no control pressure when they are not powered).
- The Blue/Green EDS solenoids have a falling characteristic curve (the maximum control pressure is obtained when the solenoid valves are not powered).