i have a nissan mistral 2.7td automatic and it wont go into fourth gear. the sellanoids are ok, the tranmission fluid and filter are ok, have tried another transmission ecu, have tried a different accelerator switch sensor, have tried another fluid heat sensor. it is at a garage who specialises in auto gearboxes and he is having difficulty diagnosing the problem. the only wiring diagram we have is for a terrano and there is a few more wires on the mistral. i have only just bought it and it has only 70 000 miles on the clock, need help. kind regards dazzer