Moxy MT 31 - Definition of Operating Modes

SHOP MANUAL MT26/31 - 08.2006 SHOP MANUAL MT26/31 - 08.2006
SHOP MANUAL MT26/31 - 08.2006 SHOP MANUAL MT26/31 - 08.2006
TRANSMISSION
Ch 2 page 60
Transmission-shutdown:
TCU has detected a severe failure that disables control of the transmission.
TCU will shut off the solenoid valves for the clutches and also the common power supply (VPS1). Transmission
shifts to Neutral. The park brake will operate normally, also the other functions which use ADM 1 to ADM 8.
The operator has to slow down the vehicle. The transmission will stay in neutral.
TCU-shutdown:
TCU has detected a severe failure that disables control of system.
TCU will shut off all solenoid valves and also both common power supplies (VPS1, VPS2). The park brake will
engage, also all functions are disabled which use ADM 1 to ADM 8.
The transmission will stay in neutral.
Definition of operating modes
Normal:
There’s no failure detected in the transmission-system or the failure has no or slight effects on transmission
control. TCU will work without or in special cases with little limitations. (see following table)
Substitute clutch control:
TCU can’t change the gears or the direction under the control of the normal clutch modulation. TCU uses the
substitute strategy for clutch control. All modulations are only time controlled. (Comparable with EST 25)
Limp-home:
The detected failure in the system has strong limitations to transmission control. TCU can engage only one
gear in each direction. In some cases only one direction will be possible.
TCU will shift the transmission into neutral at the first occurrence of the failure. First, the operator must shift the
gear selector into neutral position.
If output speed is less than a threshold for neutral to gear and the operator shifts the gear selector into forward
or reverse, the TCU will select the limp-home gear .
If output speed is less than a threshold for reversal speed and TCU has changed into the limp-home gear and
the operator selects a shuttle shift, TCU will shift immediately into the limp-home gear of the selected direction.
If output speed is greater than the threshold, TCU will shift the transmission into neutral. The operator has to
slow down the vehicle and must shift the gear selector into neutral position.