What it means
The control module detects a range or performance problem in the pressure control solenoid B control circuit.
At a glance
- Usually lights the check-engine light
How it works
Pressure control solenoid B is an electrically operated valve that helps regulate transmission hydraulic pressure. The control module compares the electrical response of solenoid B’s control circuit with its expected range or commanded behavior. It sets P0965 when that response is outside the expected range, which can involve the solenoid, wiring, connections, or module.
Common causes
Most likely first.
- Faulty pressure control solenoid B
- Open, shorted, or high-resistance wiring or connection
- Transmission control module fault
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 for solenoid B command and any pressure or shift behavior that coincides with the fault.
- Inspect solenoid B’s connector and harness for corrosion, loose pins, chafing, or other damage that could cause intermittent resistance.
- Check solenoid B coil resistance and circuit continuity against the manufacturer’s specification.
- Use the manufacturer’s procedure to compare commanded solenoid B operation with its electrical response and, where supported, transmission pressure behavior.
- If the solenoid and wiring pass, test the control module’s solenoid B driver and connections before considering module replacement.
Common fixes
- Clean and secure corroded or loose solenoid B connector terminals.
- Repair damaged, open, shorted, or high-resistance solenoid B wiring.
- Replace pressure control solenoid B if it fails electrical or functional testing.
- Repair or replace the control module only if its driver fault is confirmed.
Can I keep driving?
Avoid towing and strenuous driving if the transmission shifts harshly, slips, or engages late, because abnormal pressure control can add wear. If the vehicle enters limp mode or cannot shift predictably, stop safely and arrange assistance.
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.