722.6 Transmission Clutch Volume Indexes. Adaptations and what it does and shift groups.

722.6 Transmission Clutch Volume Indexes. Adaptations and what it does and shift groups.

Transmission adaptation is the automatic adaptation of data in the transmission control module in order to optimize shifting comfort.

  1. An adaptation is automatically performed for the following in order to compensate for tolerances and wear of clutch packs:
  2. Shift Time
  3. Filling Time
  4. Filling Pressure
  5. Control of torque converter lock-up clutch

Current symptoms of needing adaptations reset or learned:

  1. The vehicle may jolt noticeably when accelerating or driving t constant speed (possibly with subsequent humming or droning)
  • The torque converter lockup clutch is NOT adapted or poorly adapted.
  • This applies in particular if TCU/Torque Converter has been changed out within past 1000km
  • Adaptations that have been reset with my custom tcu control units will need to be driven to learn adaptations.
  • When you reset adaptions do not go out and trash on the car. TCC needs to learn, clutch volume indexes need to learn clutch clearances. 

Specific values are needed to make the shift-time adaptation, and these values are written to memory, enabling the ETC to adapt during the following shift occurrences:

  1. Accelerating-upshift adaptation: Upshifts that occur under load
  2. Deceleration-upshift adaptation: Upshifts that occur under no load
  3. Accelerating-downshift adaptation: Downshifts that occur under load
  4. Deceleration-downshift adaptation: Downshifts that occur under no load (i.e., coast-down shifts)

These values are represented in Newton meters (Nm), meaning torque; in other words, the strength of the shift. There are no ideal numbers to achieve. For example, if a 1-2 upshift that occurs under load with an eight-cylinder engine has a 190-Nm reading and the shift quality is acceptable, one may consider that the computer is able to handle and overcome the existing clutch clearance or a slight leak in the system without a flare on the shift and possible premature damage to the applying clutch. A zero number indicates that a clutch pack does not require adaptation or the clutch pack has not yet adapted. However, if an adaptation value is at its maximum and the shift is unacceptable, repair work may be required. Additional adaptation cannot be achieved when the following maximum values are reached:

  • 8- and 12-cylinder engines + or – 210 Nm
  • 6-cylinder engines + or – 180 Nm
  • 4-cylinder engines + or – 150 Nm

Shift Groups in the 722.6 5g transmission

By viewing the mechanical, hydraulic and electrical operation of a shift, you can observe that a specific solenoid and a group of valves, described as a “shift group,” cause a change in clutch application. A shift group has two phases. The transition from one gear to the next is called a “shift phase.” The second phase, once the shift is complete and the transmission is in gear, is called the “stationary phase.” Three shift groups achieve five forward speeds. In a shift phase, a shift solenoid initiates the application of one group of valves to change the clutches required for that shift. During this time the other two groups remain in the stationary phase.

The three shift groups are:

The three shift groups are:

K1/B1 (gear changes 1-2/4-5)
This group, which controls the up-shifts and downshifts 1-2/2-1 and 4-5/5-4, consists of:
• K1 clutch
• B1 brake
• 1-2/4-5 command valve
• 1-2/4-5 holding pressure shift valve
• 1-2/4-5 shift pressure shift valve
• 1-2/4-5 overlap valve
• 1-2/4-5 shift solenoid (Y3/6y3)

K2/K3 (gear change 2-3)
This group, which controls the up-shift and downshift 2-3/3-2, consists of:
• K2 clutch
• K3 clutch
• 2-3 command valve
• 2-3 holding-pressure shift valve
• 2-3 shift-pressure shift valve
• 2-3 overlap valve
• 2-3 shift solenoid (Y3/6y5)

K3/B2 (gear change 3-4)
This group, which controls the up-shift and downshift 3-4/4-3, consists of:
• K3 clutch
• B2 brake
• 3-4 command valve
• 3-4 holding-pressure shift valve
• 3-4 shift-pressure shift valve
• 3-4 overlap valve
• 3-4 shift solenoid (Y3/6y4)

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