What it means
The control module monitors the control circuit for shift solenoid B. It sets this code when it detects an open circuit in that control path.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Shift solenoid B is an electrically operated transmission valve that routes fluid to control gear changes. The control module monitors the B control path and sets P097B when it detects an open circuit, so current cannot reach or return from solenoid B as intended. The break may be in the B wire, connector terminal, or solenoid coil.
Common causes
Most likely first.
- Open in solenoid control wire
- Open solenoid coil
- Pin pushed back out of connector body
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Record freeze-frame data and review transmission live data to see what shift condition accompanied the solenoid B open.
- Inspect the solenoid B connector for a pushed-back pin, loose connection, corrosion, or a plug that is not fully seated.
- Trace the B control wire for a break, damaged insulation, or a failed connection.
- Test continuity through the B control wire and connector using the vehicle wiring diagram and specified isolation procedure.
- Measure solenoid B coil resistance and compare it with the manufacturer’s specification to check for an open coil.
- Evaluate module control only after the B circuit, connector, and solenoid coil pass their checks.
Common fixes
- Reseat or repair a pushed-back or loose terminal at the solenoid B connector.
- Repair an open solenoid B control wire or failed wiring connection.
- Replace shift solenoid B if its coil is open.
- Repair or replace the transmission control module if tests confirm a module-side control fault.
Can I keep driving?
An open solenoid B circuit can cause harsh or missing shifts and may trigger limp mode; avoid heavy loads and long trips. Stop if the vehicle slips or cannot shift safely, because continuing may 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.