Aw 55-50SN Shift Modes

[precopster]

Some info courtesy of the Sonnax website:

Volvo Shift Modes
Economy Mode – This mode is used by TCM under normal acceleration. The TCM provides the earliest possible upshifts and lockup for best economy. The TCM adjusts oil pressure to provide smooth shifts and engagements.

Sport Mode – The TCM changes from economy to sport mode if the accelerator pedal is pressed down quickly and the vehicle exceeds 31MPH. In sports mode the shift points are raised to provide the best performance and down shifting occurs at lower engine RPM. When the accelerator pedal is moved less quickly, the TCM resumes economy mode automatically.

Extreme Mode – Extreme mode is another way of saying kick-down. The TCM selects the lowest possible gear, for the vehicle speed, when the throttle is depressed to the floor.

Winter Mode – Winter mode is selected by using the "W" button on the top panel of the gear selector assembly. A warning lamp in the instrument cluster illuminates when winter mode has been selected. When winter mode is activated, the transmission will start out in 3rd gear to provide maximum traction on slippery surfaces. Depending on manual gear selection, the following shift combinations can be obtained.

D – The transaxle starts in 3rd gear, automatically shifting between 3rd, 4th, and 5th gears.
4 – The transaxle starts in 3rd gear and automatically shifts to 4th gear earlier than economy mode in D range. 5th gear is locked out.
3 – The transaxle starts in 3rd gear with no up shifts or down shifts.
L – The transaxle starts in 2nd gear with no up shifts or down shifts.
At wide-open throttle in winter mode, the transaxle uses all gears for maximum performance.

Catalytic Converter Start – This function helps the engine to reach operating temperature by preventing converter lockup and delaying the 1-2 and 2-3 upshifts when the engine is cold. This is a normal function.

Temperature Controlled Lock-up – If the transmission temperature rises excessively as a result of a heavy load with high ambient temperature conditions, the torque converter clutch is applied to reduce heat generated by the torque converter. If the temperature drops below 20°C, (68°F), lock-up will be inhibited.

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).
Note: The friction properties of this transmission fluid are different from other fluids due to the large amount of converter clutch slip. Failure to use the correct fluid will cause transmission damage and codes.

Driving Uphill – To reduce shift business, the TCM may change the shift pattern slightly when driving uphill.

Neutral Control – (This function is not available on all models). Neutral control is when the TCM disengages the forward clutch, (C1), at a stop with the brake applied. This reduces the load on the engine, therefore reducing engine vibration and improving fuel economy. When the brake is released the forward clutch engages. The following conditions must be met before the neutral control function will be allowed:

Manual shifter must be in D, 4 or 3. Neutral control will not work in winter mode or when Geartronic is selected.
Transmission oil temperature must be above 10°C or 50°F.
Throttle position must be less than 3%.
Brake pedal must be depressed.
Vehicle speed must be zero MPH.
Engine speed must be less than 1500 RPM.
There is a 2 second delay once the vehicle has stopped in the D position and a 5 second delay when shifted from N to D.

Shifting Using Geartronic
When the shifter is moved to the Geartronic position, the transmission remains in the hydraulic "D" position. When the shifter is moved to the + or – positions, the gear selector module sends a signal to the TCM to shift the transmission up or down. The driver information module changes the symbol on the instrument cluster from D to the gear that has been selected. A signal is sent to the gear selector module to light the M and turn off the other LED's on the shifter console. The TCM determines if the shift can be carried out and activates the appropriate solenoids. The TCM will override the driver's command under certain circumstances. The following applies during Geartronic shifting:

Only 1st, 2nd, or 3rd gears can be selected from a stop. The transmission will not up shift into 4th gear until a speed of at least 19MPH has been reached. The transmission will not up shift into 5th until a speed of at least 25MPH has been reached.
Automatic down shifting occurs below certain speeds if driver forgets to manually down shift transmission. Manual up shifting is required after automatic down shifting has occurred.
Kick-down is not available in Geartronic mode.
The TCM will not allow the transmission to be manually down shifted if the engine speed would exceed 6000 RPM.
If the transmission temperature gets too high, the TCM will select the correct gear so that lockup can be used.
Torque converter lock-up is only possible in 3rd, 4th, and 5th.

Volvo Adaptive Learning
Performing the adaptive learn procedure on a Volvo requires a VADIS (Volvo factory scanner) to put the TCM in the "Control Module Adaptation" mode. Some vehicles do not have this function available and will need to have the TCM software reflashed so that the control module adaptation mode will work. The TCM will not go into adaptation mode unless the transmission oil temperature is between 150°F and 230°F. The TCM will not adapt in Geartronic or Winter Mode. While the TCM is in the Adaptation Mode, the orange triangle in the center of the instrument cluster will flash when the adaptation has been completed for a particular shift.

To Adapt the Up Shifts:

Use the "D" position. Accelerate from a stop at a light throttle, about 1400 rpm, through the gears to 4th, keeping the throttle steady. Come to a stop and repeat until the orange triangle flashes after each shift.
Next, accelerate from a stop though all five gears at a throttle opening of about 1800 rpm, keeping the throttle steady. Come to a stop and repeat until the orange triangle flashes after each shift.
Finally, accelerate through the gears at a throttle opening of 2500 rpm. Repeat until the orange triangle flashes after each shift.
To Adapt the Down Shifts:

Use "D" position. While driving at about 45 mph in 5th gear release the throttle and lightly brake to a stop. Repeat this procedure until the orange triangle flashes after each downshift.
To Adapt the Garage Shifts:

With the engine idling and the brake pedal depressed, shift to "N" and wait 5 seconds, now shift to "R", wait 5 seconds then shift to "N". Repeat this procedure until the orange triangle flashes.
Repeat the above procedure for "D".
To Adapt the Neutral Control Function:

Note: Not every Volvo has the Neutral Control Function.

While driving at about 5 mph in "D", slowly come to a stop. Repeat this procedure until the orange triangle flashes.
With the engine idling and the brake pedal depressed, move the shifter to "D" and wait about 25 seconds for the orange triangle to flash. This lets you know that the TCM is ready to adapt. Once the flash is seen, release the brake and allow the vehicle to crawl forward. Repeat this procedure until the orange triangle flashes just after the brake pedal is released.
Once all of the adapts have been learned, turn off the ignition and the TCM will exit the adaptation mode.

For more precise information see Volvo Tech Bulletin # 43-27 for 2001 S60,V70,V70VC, and XC90 2.5T.For all other Volvos using the AW55-50 transmission, see Volvo Tech Bulletin # 43-20.

[regent]

This is an awesome piece of knowledge; thanks for putting it together. It willl help a lot in understanding the trany's normal behavior and dealing with its hickups.

If I may add a note on Neutral CTRL: I recall this feature was removed with the introduction of the new firmware when Volvo made it possible to invoke relearn mode in VIDA (it's in the changelogs somewhere). The Neutral CTRL used to be harmful to the old arrangement (before the introduction of modified solenoid packs).
Thanks!

[T5AUS]

Great info Mike, thanks for posting, how's things

[precopster]

I'm doing research about the repair procedures on these transmissions as I have a '02 S60 AWD with harsh downshifts and occasional banging from 3rd to 2nd gear.

Also I'm about to drop a '01 XC70 gearbox that has no reverse and loading in P and N and I'm out there fishing for info.

Also I found this excellent video from a guy named Hiram who rebuilds them: [YouTube] [/YouTube]

Still can't get the hang of embedding You Tube

[LASteve]

Thanks for this!

[kymg]

Good work Mike

But I wonder is it physically possible to make automatic transmissions more complicated. I thought heart surgery was tricky.

Maybe this is what auto transmission designers do for a laugh - they are snickering behind their hands right now.

Cheers

[regent]

I thought heart surgery was tricky.

Heart surgery is a much simpler job than what ordinary people think of it:
Consider replacing the valves on a two-cylinder engine (with the engine running under load).

[precopster]

Refurbished the solenoids and valve body on the S60 AWD with the Transgo kit over the past 2 days. THAT WAS ONE TOUGH JOB. Wait for it though......transmission's absolutely perfect with no flares, no downshift banging and no part throttle hard shift into 2nd gear. Topped up with another 4 litres of Nulon JWS 3309 compliant synthetic (that makes 12 litres now)

Didn't even bother to do an adaptation as after a 10 kilometre drive it's flawless.
Car is a gem

[T5AUS]

Great work Mike, looks like you cracked it

[precopster]

Next up is the XC70's transmission. That one will be a bit tougher but I won't consider putting it back together without the Transgo kit. I'll order another kit soon and post up some info while I'm rebuilding it.