Scheme 126
Scheme 127
Transmission Description
The 5R55S has the following features
- five forward speeds
- electronic shift, pressure, and torque converter clutch controls
- three compound planetary gearsets
- three bands
- three multi-plate clutches
- two one-way clutches
All hydraulic functions are directed by electronic solenoids. The solenoids control
- static engagement feel.
- shift feel.
- shift scheduling.
- modulated torque converter clutch (TCC) applications.
- engine braking utilizing the coast clutch and band.
- manual first and second timing.
- reverse inhibit timing.
Scheme 128
Scheme 129
All vehicles are equipped with a Vehicle Certification Label, located on the driver side door lock post. Refer to the code in the space marked TR. For model, service ID level or build date information, refer to the transmission service ID tag located on the transmission case.
Electronic System Description
The powertrain control module (PCM) and its input/output network control the following transmission operations
- shift timing.
- line pressure (shift feel).
- torque converter clutch.
The transmission control strategy combined with the engine control provides optimum powertrain operation under all conditions. When determining the best operating strategy for transmission operation, the PCM uses input information from certain engine-related and driver-demand related sensors and switches.
In addition, the PCM receives input signals from certain transmission-related sensors and switches. The PCM also uses these signals when determining transmission operating strategy.
Using all of these input signals, the PCM can determine when the time and conditions are right for a shift, or when to apply or release the torque converter clutch. It will also determine the pressure needed to optimize shift feel. To accomplish this the PCM uses three pressure control, one torque converter clutch, and four shift solenoids to control transmission operation.
The following provides a brief description of each of the sensors and actuators used to control transmission operation.
Normal Operation
The shift and torque converter clutch solenoids allow the transmission shift under normal conditions.
The transmission fluid temperature monitors the temperature of the fluid in the transmission pan.
The transmission range sensor allows the vehicle to be started in PARK and NEUTRAL. The transmission range sensor tells the PCM what position the manual lever is in. Will illuminate the reverse lamps.
The three pressure control solenoids are used to control transmission operating pressure, band and clutch application pressures.
The three speed sensors are used in determining the correct pressures, torque converter engagements or shift scheduling.
The shift and converter solenoids will manually open and close.
The shift lever will not come out of PARK unless the key is in the ON position and the brake pedal is depressed.
When placing the range selector lever in a selected gear (P, R, N, D, or (D)) the transmission will be in the correct gear for what was selected.
When the TCS switch is depressed the transmission will either disengage or engage the overdrive function.
When the TCS switch is depressed a light on the dash will illuminate O/D OFF, when the TCS switch is depressed a second time the lamp will go off.
When the TCS switch is depressed, a light on the dash will illuminate O/D OFF. When the TCS switch is depressed a second time, the lamp will go off.