ناقل الحركة ينزلق أو لا يشتبك

A transmission not transmitting the torque it is asked to — a clutch pack slipping or a gear failing to engage. It is a symptom recorded as a cause because of what it produces elsewhere: the module compares input against output speed, finds a ratio the gearbox should not be able to produce, and stores codes naming ratios and speeds rather than the slip itself.

Everything cheap has to be ruled out before the expensive conclusion. Low or degraded fluid, a stuck solenoid, a worn valve body and low line pressure all present as slip. Fluid condition and line pressure are the two measurements that settle it — and debris on the sump magnets converts a suspicion into a finding, which is what should decide between a repair and a replacement.