Honda’s Sport Hybrid i-DCD. Click to enlarge.

The Sport Hybrid i-DCD. Both the Fit Hybrid and the Vezel Hybrid are equipped with Honda’s Sport Hybrid Intelligent Dual Clutch Drive (i-DCD), a one-motor hybrid system suited for small-sized vehicles. The i-DCD drive unit combines a newly developed inline 4-cylinder 1.5L Atkinson cycle engine and the 7-speed DCT system with a built-in high-output motor and a lithium-ion battery to improve efficiency by more than 30% compared to a conventional one-motor hybrid system.

All-electric mode is enabled during startup and low- to medium-speed cruising by using the clutches to disengage the engine; the system also contributes to the improvement of fuel economy by increasing energy regeneration using the clutches to disengage the engine during deceleration.

The Vezel Hybrid is also equipped with Honda’s original Real Time AWD, which controls torque distribution to the front and rear wheels precisely through electronic control.

7-speed DCT with high-output motor. Click to enlarge.

The 7-speed DCT. Dual clutch transmissions (DCT) shift gears using two clutches: one for the odd- and one for the even-numbered gears. The simple inter-gear structure minimizes power loss, increases fuel efficiency, and realizes a sharp response and direct acceleration feel. With the Sport Hybrid-iDCD, the odd and even axes are positioned in parallel, with a planetary first gear reducing the unit’s length. The high-output motor is so small, it fits inside the transmission case.

Honda created an extremely compact DCT unit by designing the first gear as a planetary gear, thus decreasing its size in relation to the constant mesh gears to the extent that it can be housed within the center space of the motor.

Structure of the 7-speed DCT with high-output motor. Click to enlarge.

The earlier DCT-related recalls/service campaigns. The first DCT-related recall was issued on 24 October 2013. Due to an incorrect software program for the DCT control computer, some vehicles equipped with the 7-speed DCT could have experienced a blinking of the transmission warning lamp, the display of the service notification indicator on the meter display, an inability to start driving when first gear does not engage and the ability to drive only with odd-numbered gears when second gear does not engage. The total number of vehicles subject to this recall was 4,883 units of the Fit Hybrid.

The second service campaign was issued on 20 December 2013. Due to an incorrect software program for the DCT control computer, some vehicles equipped with the 7-speed DCT could have experienced the non-engagement of gears, a delay in the ability to begin driving, the blinking of the transmission warning lamp, and the display of the service notification indicator on the meter display. The total number of vehicles subject to this recall was 36,100 units of the Fit Hybrid.

Together with this service campaign, Honda notified a recall for the following reasons:

• The incorrect program for the engine control unit (ECU) could have caused unstable engine rotations and engine stall.

• The incorrect program for the transmission driver unit (TDU) could have prevented the ability to drive the vehicle from a parked position.

• The incorrect program for the hydrostatic clutch actuator (HCA) could have prevented the vehicle from moving forward or backward.

The current, third recall. Due to the non-engagement of first gear, some vehicles equipped with the 7-speed DCT may experience the failure to begin driving, backward rolling on an incline, and a failure to accelerate. Affected vehicles may take extra time to re-accelerate or to begin driving. The recall population includes vehicles that were subject to the first and second market actions.

The number of vehicles subject to this recall are 70,929 units of the Fit Hybrid and 10,424 units of the Vezel Hybrid, for the total 81,353 units.

As the remedy for the latest recall, Honda will first check each DCT’s gear change history. For vehicles with a gear change history that indicates the non-engagement of gears, Honda will replace the DCT component in order to mitigate against the possible damage to internal parts of the DCT and then change the control software program. Honda is planning to begin installing the new control program on 21 February 2014.

For vehicles with a gear change history that does not indicate non-engagement of gears, Honda will provide advice for the use of vehicles as an interim step and begin changing the software control program on 21 February 2014).

Honda has suspended the delivery of all affected models, currently being produced at Yorii Plant of Saitama Factory and Suzuka Factory, until the installation of the new software program is completed. Moreover, Honda took the necessary actions to suspended customer delivery of affected models that are already located at Honda dealerships until the installation of the new program is completed.

Honda said that it “deeply regrets” the considerable inconvenience experienced by its customers and other affected parties less than six months from the introduction of these models.