January 01, 2013

Volvo 55-50/51SN Electronic Functions

Normal Shifting Programs

  • Economy Mode - Under normal acceleration, the TCM provides the earliest possible upshifts and lockup for best economy. Adjusts oil pressure to provide smooth shifts and engagements.
  • Sport Mode - If the accelerator is pressed quickly and speed exceeds 31MPH, shift points are raised to provide the best performance. Downshift occurs at lower engine RPM. If the accelerator is moved less quickly, the TCM automatically resumes economy mode.
  • Extreme Mode - Another way of saying "kickdown." The TCM selects the lowest gear for vehicle speed when the throttle is depressed to the floor.
  • Winter Mode - Use the "W" button on the top panel of the gear selector assembly. A warning lamp on the instrument cluster illuminates and the transmission starts in 3rd gear to provide maximum traction. Depending on the gear selected, the following can occur:
    • D-starts in 3rd and automatically shifts between 3rd, 4th and 5th.
    • 4-starts in 3rd and automatically shifts to 4th earlier than economy in D range, with 5th gear locked out.
    • 3-starts in 3rd with no up/downshifts.
    • L-starts in 2nd with no up/downshifts.
    • At wide open throttle in winter mode, all gears are used for max performance.
  • Catalytic Converter Start - Helps reach operating temperature, prevents converter lockup and delays 1-2 and 2-3 upshift when cold. This is normal function.
  • Temperature Controlled Lockup - If temperature rises excessively due to heavy load with high ambient temp conditions, the torque converter clutch applies to reduce heat. If temperature drops below 20°C (68°F), lockup is inhibited.
  • Slipping Lockup - Gives smoother lockup and reduces vibration/noise. Computer maintains 50-200 RPM torque converter clutch slip. The following conditions must be met:
    • Gear shift must be in D, 4 or 3.
    • Transmission must be in 3rd, 4th, or 5th.
    • Transmission input speed must be 1100 RPM or higher.
    • Throttle opening must be 35% or less.
    • Engine coolant must reach certain temperature. Transmission oil temperature must be 40°C (104°F), but not exceed 120°C (248°F). NOTE: Friction properties of this transmission fluid are different due to large amount of converter clutch slip. Failure to use 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 - Not available on all models. The TCM disengages the forward clutch (CI) at stop, with the brake applied to reduce load. Reduces vibration/improves fuel economy. When the brake is released, the forward clutch engages. The following conditions must be met:
    • Manual shift must be in D, 4 or 3.
    • Does NOT work in Winter Mode or Geartronic.
    • Transmission oil temperature must be above 10°C (50°F).
    • Throttle position must be less than 3%.
    • Brake must be pressed.
    • Speed must be 0 MPH.
    • Engine speed must be less than I500 RPM.
    • There's a 2 second delay once vehicle has stopped in D and a 5 second delay from N-D.

Shifting Using Geartronic

When the shifter is moved to Geartronic, the transmission remains in hydraulic "D" position. When the shifter is moved to + 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 panel from D to the gear that's selected, and a signal is sent to the gear selector module to light M and turn off other LEDs on the shifter console. The TCM determines if the shift can be carried out and activates appropriate solenoids. The TCM overrides driver's command under certain circumstances. The following applies during Geartronic shifting:

  • Only 1st, 2nd or 3rd can be chosen from stop.
  • Transmission won't upshift to 4th until 19MPH.
  • Transmisison won't upshift to 5th until 25MPH.
  • Automatic downshift occurs below certain speed if driver forgets.
  • Manual upshift required after automatic downshift.
  • Kick-down not available.
  • TCM wont' allow manual downshift if engine speed exceeds 6,000RPM.
  • If transmission temperature gets too high, TCM selects correct gear for lock-up.
  • Converter lock-up only possible in 3rd, 4th and 5th.

Resetting Adapts

Adaptive learn technology adjusts the shift/line which controls the feel of up/downshifts, neutral control function and garage shift engagements. Performing the adaptive learn procedure is necessary whenever the transmission is rebuilt/replaced, valve body is replaced or TCM is replaced. The TCM is always adapting, but at an extremely slow rate. To quickly clear/relearn adapts, the TCM must be placed into adaptation mode.

Performing adaptive learn on a Volvo requires VADIS (Volvo factory scanner) to put the TCM in "Control Module Adaptation mode." Some vehicles don't have this function and will need to have TCM software reflashed so Control Module Adaptation Mode will work. The TCM won't go into Adaptation Mode unless transmission oil temperature is between 150-230°F. The TCM won't adapt in Geartronic or Winter Mode. While the TCM is in Adaptation Mode, the orange triangle in the instrument cluster will flash when the adapt is complete for each particular shift.

  • To adapt upshifts:
    • Use "D." Accelerate from stop at light throttle (1400 RPMs) through to 4th, keeping throttle steady.
    • Stop and repeat until orange triangle flashes after each shift.
    • Accelerate from stop through all 5 gears at throttle opening of 1800 RPMs, keeping throttle steady.
    • Stop and repeat until orange triangle flashes after each shift.
    • Accelerate through gears at throttle opening of 2500 RPMs.
    • Repeat until orange triangle flashes after each shift.
  • To adapt downshifts:
    • Use "D." Drive at about 45 MPH in 5th, release throttle and lightly brake to stop.
    • Repeat until orange triangle flashes after each downshift.
  • To adapt garage shifts:
    • With engine idling and brake pressed, shift to "N," wait 5 seconds, shift to "R," wait 5 seconds, shift to "N."
    • Repeat until the orange triangle flashes.
    • Repeat procedure for "D."
  • To adapt Neutral control (Not every Volvo has Neutral Control):
    • Drive 5 MPH in "D," slowly stop.
    • Repeat until orange triangle flashes.
    • With engine idling and brake pressed, move shifter to "D." Wait 25 seconds for orange triangle to flash. This lets you know that TCM is ready to adapt.
    • Once flash occurs, release brake and allow vehicle to crawl forward.
    • Repeat until orange triangle flashes after brake is released.

Once adapts have been learned, turn off the ignition and the TCM exits Adaptation Mode.

For more info see Volvo Bulletin #43-27 for 2001 S60, V70, V70VC and XC90 2.5T. For other Volvos using AW55-50 transmissions, see Bulletin #43-20.

Other useful Volvo Bulletins:

  • TNN 43-24 - info about software upgrade to enable Adaptation Mode.
  • TNN 43-37- Upgraded servo parts. Volvo also has software upgrades to correct 2-3 flare, neutral control flare bang on engagement and 2-1 downshift thud.

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