What it means
The engine coolant flow control valve reports a supply circuit low condition. Coolant routing between engine and radiator branches cannot be commanded as expected.
At a glance
- Usually lights the check-engine light
How it works
The coolant flow control valve needs a supply circuit to power its motor while routing coolant between engine and radiator branches. This code sets when the module detects supply voltage lower than expected, which can result from a blown fuse, an open supply wire, or resistance at corroded connector pins.
Common causes
Most likely first.
- Supply fuse blown
- Open in supply wire
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light
- Engine may take longer to warm up or run hotter than usual
- Cabin heat may be weak or inconsistent
How to diagnose it
- Check freeze-frame and coolant-temperature data to see whether the supply fault coincided with poor warm-up or rising engine temperature.
- With the engine cool, inspect the valve connector and supply wiring for corrosion, looseness, abrasion, or a broken wire.
- Check the correct fuse for the coolant valve supply and inspect for a blown element or poor fuse contact.
- If supported, command the valve with a scan tool and observe whether it responds while checking supply at the connector.
- Measure supply voltage and test the supply wire and connector for excessive resistance or an open, following the manufacturer's specification.
Common fixes
- Replace a blown fuse only after checking for the cause of the overload.
- Repair an open or damaged valve supply wire.
- Clean or repair corroded, high-resistance supply connector pins.
- Confirm the valve receives proper supply and operates after the repair.
Can I keep driving?
Keep trips short and watch the temperature gauge because the valve may not be powered to route coolant correctly. Stop if temperature rises above normal or a warning appears; driving while overheated can damage the engine.
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.