B&M 120001 SHIFT PLUS 2 TRANS CONTROLLER - Manual (Page 14)

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Shift Plus 2 System Features and Operations:
Performance Mode
When Performance Mode is enabled, the TCU will use a more aggressive shift strategy (transmission will hold gears
longer and be quicker to downshift) and higher line pressure for firmer shifts. The degree to which both are affected
by enabling Performance Mode can be adjusted independently through the Advanced Options in the handheld. This
allows Performance Mode to be adjusted to suit the driver’s preferences.
Manual Shifting (Bump Up / Bump Down)
By enabling Manual Shifting, the transmission can be controlled with two buttons – one for upshift, one for downshift.
The buttons can be mounted where ever they are convenient in the vehicle – on the steering wheel, on the shift lever,
etc.
In this mode, the TCU will hold the current gear until told to shift, unless the vehicle comes to a stop. In that case, it
will downshift into 1
st gear to ensure easy acceleration away from the stop. A side effect of this feature is that the
rear wheels must be turning before the TCU will accept an upshift request.
Because the TCU will not upshift on its own when Manual Shifting is enabled, care should be taken to avoid over
revving the engine. A rev limiter in a fuel injection or ignition system can act as a safety net to protect the engine in
case the driver waits too long to upshift.
Depending on vehicle speed, the TCU may ignore downshift requests. This is done to prevent over revving the engine
and/or destabilizing the vehicle.
TCC Lockup / Forced TCC Lockup
The TCU locks up the torque converter clutch during cruising conditions for improved fuel economy and to allow the
transmission fluid to cool. In order for the TCC to lock, several conditions must be met:
- Transmission fluid warmed up
- Transmission above 3
rd gear (unless transmission fluid is overheated)
- Vehicle speed above user adjustable minimum (see MIN TCC LOCK setting)
- Throttle above idle position
- Throttle below user adjustable maximum (see MAX TCC TPS setting)
NOTE: TCC lockup can be completely disabled if desired by entering an unobtainable speed for the MIN TCC LOCK
setting. The vehicle would then always be below the minimum speed for TCC lockup.
There is also a Forced TCC Lockup mode. When the TCC APPLY wire is grounded, the TCC will lock without the
normal requirements being met. The only conditions that must be met are in place to prevent stalling if this feature is
accidentally turned on or left on:
- Transmission above 1 st gear
- Vehicle speed above 10 mph
L2 Shift Lever Position
In normal operation, the TCU controls shifting and the transmission will upshift through the gears at the appropriate
speeds up to the shift lever position. For example, it will upshift until it gets to 3
rd gear when the shift lever is in the
L3/Drive position. Putting the shift lever into the L2 position is a special case. Instead of just being the upper limit
for gear selection, it actually puts the transmission directly into 2
nd gear. This can be useful in special situations.
For example, it may help reduce wheel spin when pulling away from a stop on a slippery surface.
Speed Checks
There are vehicle speed checks in place to protect the drive train if a gear is selected (either with the shift lever or
with manual bump up / bump down shifting) that is too low for the current vehicle speed. In this case, the TCU will
not electronically execute the requested downshift. However, due to the mechanical / hydraulic makeup of a trans-
mission, the TCU does not always have absolute control over gear selection. So even though the TCU is programmed
to do all it can to protect the drive train, the driver must still use caution and common sense when requesting a
downshift. Ultimately, the well being of the vehicle and its occupants is the driver’s responsibility.