12 April 2022

Showing posts with label CVT. Show all posts
Showing posts with label CVT. Show all posts

23 December 2016

Punch Continuous Variable Transmission (VT2/VT3) Clutch Adaptation Procedure





INITIAL ADAPTATION (FACTORY/TECHNICIAN)

In order to compensate for the manufacturing tolerance, an initial adaptation for the clutch is required after:
  • a reflash of TCU software
  • replacement of TCU, or
  • a replacement of the transmission.
The CVT check light flashes once every 2 seconds if the initial adaptation is not performed* (read foot note below).

PERIODICAL ADAPTATION (USER/TECHNICIAN)

The TCU keeps adapting  to compensate for the wear and tear as you use the vehicle.
However, due to the rarity of using certain drive modes (i.e reverse), the TCU may not be able to adapt to every drive modes.
This may result in the 'engine die off' issue while reversing, due to poor clutch lock-up.

Users can perform the following adaptation procedure periodically to compensate for the wear and tear due to usage.

Adaptation can be performed without additional equipment.

CONDITIONS

Throughout the procedure
  • Vehicle being stationary
  • Accelerator pedal is not applied
  • Stable engine idling speed
  • Stable and warmed-up CVT fluid temperature
  • Foot brake is applied
PROCEDURE
  1. warm up the engine and transmission
  2. shift to Neutral (N) position for ≥ 5 seconds
  3. shift to Drive (D) position for ≥ 5 seconds
  4. shift to Neutral (N) position for ≥ 5 seconds
  5. shift to Reverse (R) position for ≥ 5 seconds
  6. repeat step 2 to step 5 for 20 times* (apply foot brake throughout this stage)
  7. shift to Drive position
  8. gradually accelerate to >50km/h
  9. gradually stop the vehicle
  10. complete

*if only the transmission is replaced, the CVT check light wouldn't flash, hence the need to repeat the shifting 20 times to make sure that the adaptation is completed. If the CVT check light is flashing, the procedure can be stopped once the CVT check light has stopped flashing and turned off.

UPDATE #1: it has also been reported that a long period power disruption to the system may cause the TCU to loose the adaptation data, hence the need to readapt it before the vehicle is driven. This is to prevent unnecessary wear in the transmission and certain drivability issue due to poor clutch engagement especially for vehicle with high mileage.

UPDATE #2: long term power disruption may cause the CVT check light to trigger once a new battery is installed. In the case that the CVT check light doesn't go off after this manual adaptation procedure is performed, send the car to the nearest SC to clear the warning.

Credit to Drex Chan 
(last update: 27 July 2015)