P00B7
Engine Coolant Flow Low/Performance
Engine cooling
Generic OBD-II
High
What it means
P00B7 means the engine control module has determined that coolant is not flowing as it should — often from low coolant, a weak or failed water pump, a stuck thermostat, or a blockage. It matters because insufficient coolant flow lets the engine overheat, which can quickly cause expensive damage, so it should be checked before driving far.
High
Can I keep driving? Be careful — this points to poor coolant circulation and a real overheating risk; if the temperature gauge climbs, stop and let it cool rather than pushing on.
Common symptoms
What you'll notice
- Check-engine light on
- Engine temperature rising higher than normal or overheating
- Coolant or temperature warning light
- Heater may blow cold from poor coolant circulation
Common causes
Most likely first
- Low coolant level or trapped air in the cooling systemLikely
- Failed or weak water pump (including electric or auxiliary pumps)Common
- Thermostat stuck closed or restricting flowCommon
- Blockage or restriction in the coolant passages or radiatorLess often
- Faulty coolant temperature or flow sensor sending a false readingLess often
How to diagnose & fix
Work through it in order
- Check the coolant level and top up or bleed trapped air first; look for leaks.
- Verify the thermostat opens and the water pump actually circulates coolant.
- Inspect the radiator and hoses for restrictions or collapse.
- Confirm the coolant temperature sensor reading matches actual temperature.
- Repair the failed component, then clear and retest while watching the temperature.
FAQ
Quick answers
Is it safe to drive with P00B7?+
Only briefly and carefully. Low coolant flow can let the engine overheat, which causes serious damage — if the gauge climbs into the hot range, stop and let it cool.
Can I just clear P00B7?+
Clearing it won't restore coolant flow. The code returns and the engine stays at risk of overheating until the pump, thermostat, or coolant issue is fixed.
Related codes
Often seen with P00B7
Read & clear P00B7 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX