Q: My car won't shift out of first gear

If the torque converter is defective that could cause shifting problems, and other symptoms as well. There are stall speed and hydraulic pressure tests than can assist in diagnosing the condition of the converter.

Other possibilities include the external controls and sensors, for example the vehicle speed sensor. Transmission related sensor outputs from the engine to the PCM, and thence to the electronic transmission controls, including the shift solenoids, should be tested because if those are not all functioning properly, you will get the stuck in gear condition you are reporting.

If there are any downloadable Diagnostic Trouble Codes from your Onboard Diagnostic system, that would certainly help to pin it down. Of course, check the fluid level to be sure it is correct as low fluid is an obvious cause of failure to shift.

If you can’t resolve the issue, a certified transmission specialist from YourMechanic can perform a diagnostic for difficult shifting to figure out the root cause of the problem for you and then let you know of your repair options.