P00B7 — Engine Coolant Flow Low/Performance

Reports low engine-coolant flow or a coolant-flow performance fault. The code concerns circulation performance and does not by itself identify a failed pump or thermostat.

Affected system: Powertrain

Symptoms

• Coolant temperature may rise unusually or fluctuate, with a cooling-system or engine warning.
• Heating performance or engine smoothness can be affected if coolant circulation is insufficient.

Possible causes

• Low coolant level or leaks, a stuck thermostat or reduced water-pump circulation.
• Incorrect coolant temperature sensor readings or damaged related wiring can also produce the reported discrepancy.

What to check

• Stop driving and allow cooling if overheating is indicated; inspect coolant level and leaks only when safe and cold.
• Compare engine and radiator coolant temperatures in live data and check related codes.
• Assess thermostat and water-pump operation using the vehicle procedure; check temperature sensors and wiring before replacing parts.

Also written as: P00B7-00, P00B700, PO0B7 (some scan tools add the fault-type byte, e.g. -00).