What it means
The transmission control module detected that the transmission remained in reverse when a different range or 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 monitors the selected range and transmission response during shifts out of reverse. P072B sets when reverse remains engaged after another range is expected, which can be caused by a stuck solenoid, restricted valve-body operation, low or degraded fluid, or an internal fault.
Common causes
Most likely first.
- Shift solenoid stuck or failed
- Valve body fault restricting reverse-to-other-range shifts
- Low or degraded transmission fluid
- Internal transmission mechanical fault
Symptoms
- Transmission remains in reverse when another range is selected
- Transmission warning light on
How to diagnose it
- Record freeze-frame and live range data to confirm which range was selected and whether the TCM continued to report reverse.
- With the vehicle stationary, brakes applied, and area clear, check that the shifter indication matches the selected position; do not force the selector.
- Check fluid level and condition using the manufacturer's procedure, and inspect for leaks or signs of overheating.
- Scan for shift-solenoid and range-sensor codes, then inspect the related transmission connectors and wiring.
- If fluid and electrical checks do not explain the fault, test solenoid and valve-body operation, followed by internal transmission checks as specified by the manufacturer.
Common fixes
- Correct low fluid and repair any leak using the specified service procedure.
- Repair a damaged connector or wiring fault in the range or shift-solenoid circuit.
- Replace a confirmed failed or stuck shift solenoid.
- Repair a sticking valve body or confirmed internal mechanical fault.
Can I keep driving?
Do not drive if the transmission remains in reverse when another range is selected; it can move in an unexpected direction and cause a collision. Keep the vehicle secured and arrange recovery.
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.