Good day to you all. I am having an issue with the AW55-50 geartronic gearbox fitted into my '04 2.4i V50 (> 130k miles) and after reading through the majority of the past 40 pages of posts in this thread I am hoping that one of you may know of a solution to my problem.
FYI: I have already had a thread on this issue in the S40/V50 forum HERE.
I acquired the car in March '19 and in November '19 I noticed an issue with it where the RPM was fluctuating at low revs. I did some research and the symptoms I am seeing match the conditions under 'Volvo Shift Modes: Locking Slip-up' but they are greatly exaggerated with the RPM fluctuation sometimes being around 300-400RPM. The occurrence is varied, it probably occurs 75% of the the times the conditions are met but when it starts to happen it is almost continual. When it occurs you can feel a change in performance, going from smooth to sluggish as the RPM fluctuates.
The Sonnax site describes the feature as follows:
https://www.sonnax.com/tech_resource...urers-part-one
Slipping Lock-up – Slipping lock-up mode allows for a smoother lock-up engagement while reducing vibration and noise. The computer maintains a 50 to 200 RPM torque converter clutch slip in this mode. The following conditions must be met for this mode to activate:
Gear shifter must be in the D, 4, or 3 position.
Transmission must be in 3rd, 4th, or 5th gear.
The transmission input speed must be 1100 RPM or higher and the throttle opening must be 35% or less.
Engine coolant must reach a certain temperature.
Transmission oil temperature must be at least 40°C (104°F), but not to exceed 120°C (248°F).
When I purchased the car, nearly two years ago it had a full main dealer service history but I could find no record of an ATF change so in April this year I took it to a local garage for a ATF change. I understand this was simply a change, not a flush. This did not resolve the issue although it did appear better for a little while.
When the conditions of the slipping lock-up feature are not met, which is generally when it goes above 2k RPM, the gearbox appears to be otherwise smooth and the engine gives strong performance with no indication of slipping from the gearbox. On a cold morning just after starting you can feel the first few changes but as soon as the temperature gauge starts to rise this goes away.
I am wondering if it simply needs a full ATF flush and a software update?