What it means
The ECM detects a circuit high fault on the coolant pump speed sensor circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The coolant pump speed sensor reports pump rotation to the engine control module. P2CCB sets when the signal circuit stays above the expected range, such as from a short to battery positive or an open sensor, leaving the module without trustworthy speed feedback.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open sensor
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light
- Possible coolant temperature warning
- Engine temperature may rise
How to diagnose it
- Review freeze-frame data and related codes to see when the high signal occurred and whether coolant temperature or pump commands changed at the same time.
- Inspect the sensor connector and signal wiring for damage, corrosion, loose pins, or unintended contact with a battery-positive wire.
- Measure the sensor signal and check its power and ground connections against the manufacturer's specification.
- With the circuit isolated as directed by the manufacturer, test the signal wire for a short to B+ and check connector continuity for an open circuit.
- Test the sensor response using the vehicle-specific procedure to distinguish an open or failed sensor from a harness fault.
Common fixes
- Reconnect or repair loose, corroded, or open sensor connector pins.
- Repair signal wiring shorted to battery positive or damaged by chafing.
- Restore a broken signal-wire connection if continuity testing confirms an open.
- Replace the coolant pump speed sensor if testing confirms it is open or fails to produce the specified signal.
Can I keep driving?
Watch the temperature gauge and stop safely if a coolant-temperature warning appears or the engine overheats. Without reliable pump-speed feedback, a cooling fault may go undetected and continued driving 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.