What it means
The transmission control module detected that the transmission remained in fifth gear when another gear was expected. The code does not identify whether the cause is electrical, hydraulic, or mechanical.
At a glance
- Usually lights the check-engine light
How it works
The TCM compares the commanded gear with transmission speed-sensor data to confirm that the selected ratio was reached. P073A sets when the transmission remains in fifth gear while the controller expects a different gear, but the code alone cannot distinguish a solenoid, hydraulic, fluid, or internal mechanical problem.
Common causes
Most likely first.
- Shift solenoid stuck or failed
- Valve body fault affecting fifth-gear shifts
- Low or degraded transmission fluid
- Internal transmission mechanical fault
Symptoms
- Transmission remains in fifth gear or does not shift as expected
- Transmission warning light on
How to diagnose it
- Save freeze-frame data and review commanded gear, actual gear or ratio, and input and output speeds to confirm when fifth gear remains engaged.
- Check for other transmission codes that may identify a shared speed-sensor, solenoid, or control problem.
- Inspect for transmission-fluid leaks and check fluid level and condition using the vehicle's specified procedure.
- Inspect the transmission wiring and connectors for damage, corrosion, loose pins, or fluid intrusion affecting shift-solenoid control.
- Use a scan tool to compare commanded solenoid states with transmission response, then test the fifth-gear-related solenoid and hydraulic or mechanical components as specified by the manufacturer.
Common fixes
- Correct a low fluid level and repair any leak, using the specified fluid and checking procedure.
- Repair damaged wiring or connector terminals in the shift-control circuit.
- Replace a confirmed faulty shift solenoid.
- Service or repair the valve body if testing identifies a fifth-gear control fault.
- Repair internal transmission damage if external electrical and hydraulic checks do not resolve the fault.
Can I keep driving?
Avoid high-speed driving if the transmission is stuck in fifth gear, since acceleration and available gear range may be limited. Stop if it slips, overheats, or shifts unpredictably, because continued driving can increase transmission damage.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.