摘要 |
A method for diagnosing damage in the shift mechanism of an automatic gearbox, involving at least one of the following steps: (a) determining an actual period needed for synchronizing a gear, comparing the actual period with a setpoint period for synchronizing the gear, and establishing whether the shift mechanism is damaged; the shift mechanism is assumed to be damaged if the actual period differs from the setpoint period; (b) moving a shift actuator to a limit stop after selection of a gear, establishing whether the limit stop that has been reached is an internal limit stop of the shift actuator or a gearbox limit stop, and establishing whether the shift mechanism is damaged; the shift mechanism is assumed to be damaged if the limit stop that has been reached is an internal limit stop of the shift actuator; (c) determining an actual engine speed during the overlap phase and comparing the actual speed with a speed range within which the engine speed is expected to lie during the overlap phase, and establishing whether the shift mechanism is damaged; the shift mechanism is assumed to be damaged if the actual speed is not within the range for the expected speed.
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