What are the reasons why an automatic transmission car does not move when shifted to R gear?
2 Answers
There are two main reasons why an automatic transmission car does not move when shifted to R gear: mechanical faults and operational issues. Mechanical faults: If components such as the transmission, oil pump, torque converter, control wiring, solenoid valves, or switches malfunction, the reverse gear may fail. The solution is to first check if the transmission has insufficient oil, whether the main oil pressure and gear oil pressure are normal, and then verify if the gear switch signal is functioning correctly. Additionally, inspect the wiring from the transmission computer to the shift solenoid valves and ensure the gear solenoid valves are working properly. If all these components are in order, it indicates an issue with the internal control system of the transmission, requiring disassembly to examine the internal actuators. Operational issues: If the electronic parking brake is not released or the gear shift is not properly engaged, the reverse gear may also fail to function. The solution is to check if the electronic parking brake is released and release it promptly if necessary. If the issue is not related to the parking brake, it is advisable to visit a repair shop to inspect whether the gear synchronizer in the transmission is stuck or if there are other faults.
When the car doesn't move in R gear, I've had experience with this issue. It could be caused by worn clutch plates inside the transmission or a faulty reverse gear failing to transmit power. Oxidized contacts on the gear selector causing signal interruption can also lead to this problem. Of course, if the brake isn't fully released or pressed too hard, the car won't move - don't underestimate this simple mistake. I've encountered cases where insufficient or degraded transmission fluid affected its flow - first check the dipstick level and how dark the fluid appears. Other possibilities include deformed shift linkage or faulty sensors misreporting position, which can be quickly diagnosed with an OBD scan. Remember not to force the gear shift as it can easily burn out more components. Immediately turn off the engine, pull over safely, and have a professional mechanic inspect the transmission's core components. Regular fluid changes as preventive maintenance can extend its lifespan and save you money. This situation poses significant driving danger and should be prioritized for immediate attention.
