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DTC codes / P0Cxx · Hybrid propulsion / P0C35

P0C35Hybrid/EV Battery Temperature Sensor F Circuit Low

P0C35 indicates that the hybrid or electric vehicle battery temperature sensor circuit designated as 'F' is reporting a voltage lower than the manufacturer's expected range, which the computer interprets as a low circuit condition. The powertrain control module sets this code when the sensor signal wire is shorted to ground or the sensor's internal resistance drops abnormally low.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaHybrid propulsion

Symptoms you may notice

  • Illumination of the check engine light or hybrid system warning light, often with no other noticeable symptoms
  • Reduced hybrid battery charging or discharging performance, leading to lower fuel economy
  • The vehicle may enter a fail-safe mode that limits power or disables the hybrid system
  • Inconsistent or incorrect battery temperature readings on a scan tool
  • Possible overheating of the hybrid battery pack if the sensor falsely reports a low temperature
  • In rare cases, the vehicle may refuse to start or shift into gear

Common causes, most likely first

  1. A short to ground in the signal wire between the temperature sensor and the control module
  2. A faulty battery temperature sensor with an internal short or low resistance
  3. Corroded, damaged, or loose electrical connectors at the sensor or control module
  4. Wire chafing or pinching against metal components, causing intermittent shorts
  5. A failed control module that incorrectly interprets the sensor signal
  6. Moisture intrusion into the sensor or connector, creating a conductive path to ground

How to diagnose and fix it

  1. Use a scan tool to verify the code and check live data for the battery temperature sensor 'F' reading to confirm it is abnormally low.
  2. Visually inspect the sensor and its wiring harness for signs of damage, corrosion, or moisture, and repair any obvious issues.
  3. Disconnect the sensor and measure its resistance with a multimeter, comparing the reading to the manufacturer's specification for the current temperature.
  4. Check the signal wire for continuity to ground with the sensor disconnected; if continuity exists, trace and repair the short.
  5. If the wiring and sensor test good, substitute a known-good sensor and clear the code to see if it returns.
  6. Inspect the control module connectors for corrosion or loose pins, and repair as needed.
  7. If all else fails, follow the manufacturer's diagnostic flow chart for control module testing or replacement.

Don't overlook the wiring harness

  • A common oversight is replacing the temperature sensor when the real problem is a chafed signal wire shorting to ground in a hidden section of the harness.
  • This code can be set by a sensor that is not completely failed but has drifted out of specification, so resistance testing at multiple temperatures is more reliable than a single check.
  • In some vehicles, the battery temperature sensor is integrated into a larger battery pack assembly, making replacement more involved and costly than a stand-alone sensor.
  • Intermittent low-voltage readings can be caused by water intrusion into the connector, which may not be obvious until the harness is flexed or the connector is opened.
  • A low circuit code does not always mean the sensor is bad; a poor ground connection at the control module can also cause the same symptom.

Can I keep driving with P0C35?

It is generally safe to drive with this code if the vehicle is operating normally, but avoid aggressive driving or heavy electrical loads that could stress the hybrid battery. If the vehicle enters a reduced-power mode or shows other warning lights, have it inspected promptly to prevent battery damage.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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