What it means
Voltage on the coolant pump clutch control line is below the expected window. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
How it works
The coolant pump clutch control circuit carries the module's command to engage the clutch. This code sets when the module detects control-line voltage below its expected range, which can prevent the clutch from engaging and reduce coolant flow under load.
Common causes
Most likely first.
- Control wire shorted to ground
- Internal short in clutch coil
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light may be on
- Engine may overheat, especially under load
- Cooling-system warning may appear
How to diagnose it
- Check freeze-frame data and live coolant temperature to determine whether the low circuit reading coincides with a clutch-on command or overheating.
- Inspect the clutch connector and control-wire harness for chafing, moisture, corrosion, loose pins, or a wire touching ground.
- With the code active, monitor the control signal while gently moving the harness to see whether voltage changes and locate an intermittent short or connection fault.
- Measure the control circuit for a short to ground and check connector contact quality, following the manufacturer's wiring information.
- Disconnect and test the clutch coil for an internal short, then compare circuit and coil results with the manufacturer's specification.
Common fixes
- Clean and secure corroded or loose clutch connector terminals.
- Repair the control wire where it is shorted to ground or chafed.
- Repair or replace a clutch coil that is internally shorted.
- Replace damaged connector terminals or wiring that cannot maintain a sound connection.
Can I keep driving?
Avoid heavy loads and stop if the engine temperature rises or a cooling-system warning appears; the low control signal may leave the clutch disengaged and cause overheating. Have the circuit checked promptly.
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.