Tech Tip: Volvo A/T-Neutral Control Function – UnderhoodService

Tech Tip: Volvo A/T-Neutral Control Function

A function called "Neutral Control" is present on all 2001 V70 and S60 cars, as well as on 2002 non-turbo V70 and S60 cars built before January 2002. When the vehicle comes to a stop, the Transmission Control Module (TCM) activates Neutral Control. Even though the gear selector is in the Drive position, a Neutral condition is engaged hydraulically in the transmission. Neutral Control disengages when the brake pedal is released or the throttle is applied.

A function called “Neutral Control” is present on all 2001 V70 and S60 cars, as well as on 2002 non-turbo V70 and S60 cars built before January 2002. When the vehicle comes to a stop, the Transmission Control Module (TCM) activates Neutral Control. Even though the gear selector is in the Drive position, a Neutral condition is engaged hydraulically in the transmission. Neutral Control disengages when the brake pedal is released or the throttle is applied.

When the neutral control function is incorrect, there are three symptoms that can be felt in the car:

1. After coming to a complete stop and keeping the brakes applied, a “thump” can be felt in the car. It’s felt about two seconds after coming to a stop.

2. When releasing the brake, there is a harsh or double re-engagement of drive.

3. When idling in “D” range with the brake applied, the engine speed oscillates (fluctuates).

In addition to these symptoms, some cars may set a DTC 012A or 012B in the TCM; these should be erased before downloading the software.

Note: Neutral Control is not active during the following:
• Transmission in “W” mode;
• Transmission in Geartronic mode;
• Gear selector in “L” range (non-Geartronic shifter); and
• Operating with high AC demand (higher idle speed).

Service Procedure:
Upgrade the TCM (software P/N 30677036). In addition to correcting the Neutral Control symptoms, this software package also improves response during power-on downshifts and minimizes 2-3 shift flare. There is no need to reset the adaptation to zero.

Technical service bulletin courtesy of ALLDATA.

For additional information, visit www.alldata.com.

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