What is the reason for the failure where the vehicle can go down but not up?
2 Answers
Check whether the lifting contactor in the vehicle control box is engaged. If it is not engaged, check whether the lifting control line is open, has a loose connection, or whether the contactor coil is damaged. If the lifting contactor is engaged but the motor makes no sound, check whether the fire-break switch is damaged. Additional information: When a mechanical failure causes the vehicle to get stuck, the fault point must be located and addressed before operation. Locate the travel switch for upward or downward movement and press it to reset it. Press the lower travel control button, and the upward movement should respond, or open the clutch switch, manually lift the vehicle upward, and then repair the control circuit.
This is a common issue, and I can explain the reasons from multiple aspects. A vehicle that can go downhill but not uphill usually indicates insufficient power under high load. Possible causes include partial engine failure, such as problems with the fuel supply system, like an aging fuel pump or a clogged filter leading to insufficient fuel pressure; or ignition system issues, such as severe carbon buildup on spark plugs causing unstable operation at high RPMs. In terms of the transmission, slipping clutches or abnormal oil pressure in automatic transmissions can lead to unstable power delivery, while in manual transmissions, excessively worn clutch plates may slip during uphill climbs. Other factors like a blocked exhaust system or a faulty turbocharger can also limit power output. It's advisable to start with simple checks, such as inspecting the fuel and coolant conditions, or taking the vehicle to a professional shop to test engine output data, to avoid getting stranded midway, which wastes time and increases risks.
