Circuit/System Verification

Vehicle ON, observe the scan tool ECM engine coolant temperature (ECT) parameter in freeze frame data. The reading should be below 125°C (257°F).
- If the ECT was above 125°C (257°F) when the DTC set, go to Symptoms - Engine Cooling and correct that concern first.
Inspect for proper coolant level in the hybrid cooling system reservoir.
- If coolant level is low refer to Hybrid Cooling System Loss of Coolant (Power Electronics) , Hybrid Cooling System Loss of Coolant (Battery - Without Anti Tamper Bracket) , Hybrid Cooling System Loss of Coolant (Battery - With Anti Tamper Bracket) .
Inspect the hybrid cooling system radiator for debris or obstruction.
- If a concern is found, repair or replace the restricted or damaged components as necessary.
Inspect for proper operation of all hybrid system coolant pumps. Refer Hybrid/EV Electronics Cooling Diagnostic .
- If a concern is found, repair or replace the coolant pumps as necessary.
Command the cooling fans through all operating speeds.
- If the cooling fans do not operate in all speeds, refer to Hybrid/EV Electronics Cooling Diagnostic .