A/T - AW55-50 Harsh Upshifts/Downshifts
NO: 43-20DATE: 7/12/2002
MODEL:
S/V 70 S/V 40, C70
SUBJECT:
Adaptation Procedure - S/V 70, S/V 40, and C70 with AW 55-50 Transmission
REFERENCE:
Bulletin Number 43-18 and 43-19
THIS BULLETIN SUPERCEDES THE PREVIOUS BULLETIN DATED 1/11/2001.
Please update your files. Update refers to Model and Subject Line.
DESCRIPTION:
The AW 55-50 automatic transmission used in certain MY 00 S/V 70's and all MY 01 S/V 40, C70, vehicles incorporate adaptive functions. If a software download is performed, the transmission or TCM are replaced, or the vehicle is new, an adaptation procedure may need to be performed. Complaints of harsh gear engagement and harsh upshifts/downshifts are indications that the adaptation procedure may not have been completed.
SERVICE:
1. In order to perform the adaptation procedure the ATF temperature must be within 65-110°C (150-230°F). Accelerating the vehicle in Winter mode will help raise the fluid temperature if it is below 65°C (150°F). A stall test should not be used to heat up the fluid. Read the temperature with VADIS. The adaptation will not be completed if the fluid temperature is not within this range.
2. With the ATF within the specified temperature range start driving the vehicle with light throttle. Using approximately 15% throttle keep a steady pedal through all the gears until 4th. gear is reached. It is not possible to reach 5th. gear with this pedal position. Repeat until the shift quality is OK at each gear change.
3. Repeat step 2 with approximately 25% pedal application. Keep a steady pedal through all the gears until 5th gear is reached.
4. Accelerate to approximately 45 mph (72 km/h) and decrease the speed by lightly applying the brake until the vehicle stops. This should take approximately 7 seconds. Repeat this until the quality of the downshifts are OK.
5. Apply the brake and put the gear selector in the P position. Move the lever to the R position and wait 5 seconds. Move the selector back to P position and wait another 5 seconds. Repeat until the R engagement is OK.
6. Repeat the procedure in step 5 moving between N position and D position until the D engagement is OK.
Warranty Information