01 Why Does My Diesel Engine Take So Long to Warm Up? • 02 iStop: The Revolutionary Brake-Activated Auto Stop-Start Sy… • 03 System Too Lean: Causes, Symptoms, and Troubleshooting of a… • 04 Silent But Deadly: The Secret Dangers of Worn Ball Joints • 05 How to Prevent Catalytic Converter Failure and Maintain Its… • 06 You Might Stall On The Highway If You Keep Ignoring That Ra… • 07 Unlocking the Power of Differential Lock: Traction, Problem… • 08 B0017 and B0018 Codes: Right Front or Passenger Frontal Dep… • 09 The Hidden Tech Inside Modern Cars Most Drivers Don’t Under… • 10 Why Did Your Car Suddenly Turn Off While Driving? The Top R… •

DTC codes / P0Cxx · Hybrid propulsion / P0C98

P0C98Hybrid/EV Battery Temperature Sensor L Range/Performance

P0C98 indicates that the hybrid or electric vehicle battery pack's temperature sensor 'L' is reporting a signal that falls outside the expected range or performance criteria, so the battery energy control module cannot trust that sensor's reading. The computer has detected either an implausible voltage, an out-of-range resistance, or a correlation error between sensor L and the other battery temperature sensors.

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

Symptoms you may notice

  • Illumination of the hybrid system warning light or service vehicle soon message
  • Reduced electric-only range or forced engine operation in a plug-in hybrid
  • A noticeable drop in available battery power or acceleration
  • The battery cooling fan running constantly or not at all
  • Often no symptoms besides the warning light, especially in mild weather
  • In rare cases, the vehicle may refuse to start or shift into gear

Common causes, most likely first

  1. Faulty battery temperature sensor L itself, due to age, vibration, or thermal cycling
  2. Damaged or corroded wiring or connector at sensor L or along its harness
  3. Open or short circuit in the sensor signal or return circuit
  4. High-voltage battery pack overheating from a failed cooling fan or blocked duct
  5. Battery energy control module software needing an update or recalibration
  6. Internal fault in the battery energy control module affecting sensor reference voltage
  7. Moisture intrusion into the battery pack causing intermittent sensor readings

How to diagnose and fix it

  1. Connect a scan tool and record all battery temperature sensor readings to see if sensor L is stuck, erratic, or offset from the others
  2. Visually inspect sensor L, its connector, and the harness for damage, corrosion, or loose pins
  3. Measure the resistance of sensor L and compare it to the expected value for the ambient temperature
  4. Check the sensor signal circuit for shorts to ground or power and for excessive resistance
  5. Verify the battery cooling system operates correctly and that the pack is not genuinely overheating
  6. If wiring and cooling are good, replace sensor L and clear the code
  7. After repair, perform a battery pack temperature sensor learn or calibration procedure if required by the manufacturer

Why sensor L often is not the real culprit

  • A weak or failing 12-volt auxiliary battery can cause erratic sensor readings and set this code without any fault in the high-voltage pack.
  • Corrosion inside the battery pack connector is a common cause that a simple wiggle test will not reveal; the pins must be inspected under good light.
  • The code can be set by a genuine overheating event from a blocked cooling duct or failed fan, so always verify pack temperature before condemning the sensor.
  • Some vehicles require a battery energy control module software update to correct a false sensor L range error before any parts are replaced.
  • Sensor L is one of several pack temperature sensors, and a single skewed sensor can make the whole pack appear to have a temperature correlation fault.

Can I keep driving with P0C98?

You can usually drive the vehicle short distances at moderate speed to a repair shop, but avoid heavy acceleration, sustained high speeds, and DC fast charging until the fault is diagnosed. If the hybrid system warning is accompanied by a red battery temperature message or reduced power, stop driving and have the vehicle towed.

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.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage