01 Why Cars That Take Longer To Start In The Morning Are Often… • 02 Slippery Roads: The Ultimate Guide to Safe Driving • 03 P0015 B Camshaft Position - Timing Over Retarded (Bank 1) • 04 What can cause difficulty starting in a petrol engine? | Q&A • 05 Mechanics Say This Common Driving Behavior Causes More Engi… • 06 That Rotten Egg Smell From Your Exhaust Isn't Normal: Here'… • 07 Is the Toyota Supra Saying Goodbye? Here's What We Know • 08 Pushing the Limits: How Long Can You Really Go Without an O… • 09 Why Disconnecting Your Car Battery for Storage is a Good Ba… • 10 A Watch Collector Spent $49.4 Million on Four Rolexes and t… •

DTC codes / P0Cxx · Hybrid propulsion / P0CE2

P0CE2Hybrid/EV Battery Pack Coolant Control Valve A Control Circuit Low

P0CE2 indicates that the hybrid or electric vehicle battery pack coolant control valve A control circuit has been detected as low by the vehicle's control module. The computer monitors the electrical circuit that commands the valve and has seen a voltage or current condition below the expected range, which can prevent proper coolant flow through the battery pack.

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

Symptoms you may notice

  • Illumination of the check engine light or service vehicle soon message
  • Often no symptoms besides the warning light
  • Reduced hybrid/EV performance or power output
  • Battery pack overheating warning or reduced charging rate
  • Cooling fan running excessively or not at all
  • In some cases, the vehicle may enter a limp mode

Common causes, most likely first

  1. Faulty coolant control valve A (sticking, seized, or internally shorted)
  2. Damaged or corroded wiring harness or connector at the valve
  3. Open or short to ground in the control circuit
  4. Failed control module driver for the valve circuit
  5. Poor electrical connection at the control module
  6. Aftermarket or incorrect valve installed previously

How to diagnose and fix it

  1. Inspect the valve connector and wiring for corrosion, damage, or loose pins
  2. Check the control circuit for continuity and short to ground using a multimeter
  3. Test the valve actuator with a known-good signal or scan tool bidirectional control
  4. Verify power and ground supplies to the control module
  5. Replace the coolant control valve if electrically faulty
  6. Repair or replace damaged wiring harness sections
  7. Clear codes and perform a road test to confirm the repair

What the low circuit code really means

  • A low circuit code often results from a poor ground connection rather than a failed valve, so inspect ground points before condemning the valve.
  • The valve may be mechanically stuck and drawing low current, which the module interprets as a circuit fault even though the wiring is intact.
  • Some vehicles set this code intermittently due to coolant contamination or debris in the valve, so a flush may be needed after replacement.
  • The control module may command the valve to a default position when the fault is present, masking symptoms until the code is cleared.
  • Always check for technical service bulletins (TSBs) for the specific vehicle, as some models have known connector issues.

Can I keep driving with P0CE2?

It is generally safe to drive short distances to a repair shop, but avoid aggressive driving or heavy loads that increase battery heat. Prolonged driving with this code can lead to battery overheating and reduced performance, so schedule diagnosis soon.

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