Honda Multi Matic Transmission/CVT

System Description

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General Operation

The Honda Multi Matic; continuously variable transmission (CVT) is an electronically controlled automatic transmission with drive and driven pulleys and steel belt. The Honda Multi Matic provides non-stage speeds forward and 1 reverse. The entire unit is positioned in line with the engine.

Transmission

Around the outside of the flywheel is a ring gear which meshes with the starter pinion when the engine is being started. The transmission has 4 parallel shaft: the input shaft, the drive pulley shaft, the driven pulley shaft and the secondary gear shaft. The input shaft is in line with the engine crankshaft. The drive pulley shaft and driven pulley shaft consist of movable and fixed face pulleys. Both pulleys are linked by the steel belt.

The input shaft includes the sun gear and planetary gears with carrier. The drive pulley shaft includes the drive pulley and forward clutch. The driven pulley shaft includes the driven pulley, start clutch and the secondary drive gear which is integral with the park gear. The secondary gear shaft is positioned between the secondary drive gear and the final driven gear. The secondary gear shaft includes the secondary driven gear and the final drive gear which serves to change the rotation direction, because the drive pulley shaft and driven pulley shaft rotate the same direction. When certain conditions of the planetary gears in the transmission are engaged by the clutch and the reverse brake, power is transmitted from the drive pulley shaft to the driven pulley shaft to provide , , and positions.

Electronic Control

The electronic control system consists of the powertrain control module (PCM), sensors and solenoid valves. Shifting is electronically controlled for comfortable driving under all conditions. The PCM is located below the dashboard, behind the glove box.

Hydraulic Control

The lower valve body assembly includes the main valve body, the secondary valve body, the CVT pulley pressure control valve assembly, the CVT speed change control valve assembly and the CVT start clutch pressure control valve assembly. They are positioned on the lower portion of the transmission housing.

The main valve body contains the PHC (pressure high control) valve, the lubrication check valve, the cooler relief valve and the CPC (clutch pressure control) valve. The secondary valve body contains the start clutch accumulator valve, the shift inhibitor valve, the clutch pressure reducing valve, PH (pressure high) regulator valve and the lubrication regulator valve. The CVT pulley pressure control valve assembly contains the PL (pressure low) regulator valve and the HLC (high and low pressure control) valve which is joined with the HLC solenoid. The shift inhibitor solenoid valve is positioned on the CVT pulley pressure control valve assembly. The CVT speed change control valve assembly contains the pulley control valve and the shift control valve which is joined with the shift control solenoid. The CVT start clutch pressure control valve assembly contains the start clutch control valve which is joined with the start clutch control solenoid. The solenoids are controlled by the PCM. The manual valve body is bolted on the intermediate housing and contains the manual valve and the reverse inhibitor valve.

The ATF pump is located on the transmission housing and it is linked with the input shaft by the sprockets and the sprocket chain. The pulleys and clutches receive fluid from their respective feed pipes and the reverse brake receives fluid from internal hydraulic circuit.

Shift Control

The PCM controls to shift pulley ratio the solenoids, while receiving input signal from the various sensors and switches located throughout the vehicle. The PCM actuates the shift control solenoid and the shift control valve to change the shift control pressure. The shift control pressure is applied to the drive and driven pulleys and pulley ratio is changed to their effective ratio.