摘要 |
<p>When a speed is to be changed, a transmission controller of the present invention judges a load, the quantity of a remaining oil in each transmission clutch (F, R, 1-4) and a speed change path, from which stage to which stage, and changes an electrical instruction pattern to be applied to pressure control valves (51-56) for required transmission clutches in accordance with the result of this judgement so that the speed change can be made always smoothly irrespective of a driving condition. The electrical instruction (C1-C4) to be applied to each pressure control valve (51-56) is compared with an output current (I1-I6) of a drive circuit and with the output (S1-S6) of clutch pressure detection means (101-106) and clutch abnormality is detected on the basis of the result of this comparison. When abnormality is detected, suitable measures are taken to reliably prevent double engagement of clutch.</p> |