What it means
The HV battery pack coolant control valve B reports a control circuit/open condition.
At a glance
- The engine or gearbox may go into limp mode
How it works
Coolant control valve B directs coolant through the hybrid or electric battery pack cooling circuit when commanded. P0D1A means the module detects an open in valve B's control circuit, so it may be unable to operate the valve and maintain the requested battery cooling.
Common causes
Most likely first.
- Open in valve control wire
- Open actuator
- Pin pushed back out of connector body
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Read freeze-frame data and battery cooling live data, including valve B's command and reported response, to establish when the open was detected.
- With the vehicle powered down as specified by the manufacturer, inspect valve B's connector for a pushed-back pin, poor seating, corrosion, or coolant contamination.
- Trace valve B's control wiring for breaks, chafing, or damaged insulation, paying attention to connector strain points.
- Use the wiring diagram to test continuity through valve B's control wires and actuator, isolating the circuit as directed by the manufacturer.
- Compare actuator and circuit test results with the manufacturer's specification, repair the open, and verify valve B responds to commands.
Common fixes
- Reseat the connector and correct a pushed-back terminal.
- Repair an open or damaged valve B control wire.
- Clean or replace a corroded connector terminal.
- Replace valve B's actuator if it fails the specified circuit test.
Can I keep driving?
Avoid heavy acceleration, steep climbs, and charging if the vehicle limits power or reports a battery cooling fault, since inadequate cooling can restrict operation or charging. Stop if a temperature warning appears and follow the vehicle's instructions.
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.