P0CD8: Hybrid/EV Battery Pack Coolant Temperature Sensor B Circuit High
What to do
As P0C42 and P0CD5. The useful number is the difference between inlet and outlet — if they read almost the same while the pack is working, coolant is not moving even if the pump sounds like it is.
What this code means
The pack's second coolant temperature sensor is reading above its valid range. Why two sensors give a measurement rather than two readings is at P0CD5, and the family's argument at P0C42.
Likely causes
Start here
- Faulty engine coolant temperature sensor · moderate
- Corroded or loose connector · easy
Less common
- Low coolant level · easy
- Coolant leak into the sensor connector · moderate
Symptoms
Components involved
Information, not instruction
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Community experience
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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
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