Failed electric coolant pump motor or impeller seized due to debris or corrosion; Open or shorted wiring in the pump power or ground circuit; Blown fuse or faulty relay supplying power to the pump; Corroded or loose electrical connector at the pump or control module; Faulty coolant temperature sensor providing incorrect feedback to the control module; Software glitch or internal fault in the control module driving the pump

DTC codes / P2Dxx · Hybrid propulsion / P2D05

P2D05Motor Electronics Coolant Pump B Stuck/Stalled

Q: What does code P2D05 mean?

Motor Electronics Coolant Pump B Stuck/Stalled. P2D05 indicates that the engine control module has detected a stuck or stalled condition in the electric coolant pump circuit designated as 'B', which is typically the motor electronics cooling pump responsible for circulating coolant through the inverter or power electronics. The computer monitors pump operation via feedback signals and sets this code when the pump fails to respond to commands or reports an implausible speed or current draw.

P2D05 indicates that the engine control module has detected a stuck or stalled condition in the electric coolant pump circuit designated as 'B', which is typically the motor electronics cooling pump responsible for circulating coolant through the inverter or power electronics. The computer monitors pump operation via feedback signals and sets this code when the pump fails to respond to commands or reports an implausible speed or current draw.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the check engine light or service vehicle soon message
Often no symptoms besides the warning light, especially if the pump is only intermittently stalling
Reduced power or limp mode due to overheating protection for the electronics
Overheating warning message or temperature gauge fluctuation
Cooling fan running excessively or continuously after shutdown
Audible whining or lack of pump noise when the ignition is turned on

Common causes, most likely first

Failed electric coolant pump motor or impeller seized due to debris or corrosion
Open or shorted wiring in the pump power or ground circuit
Blown fuse or faulty relay supplying power to the pump
Corroded or loose electrical connector at the pump or control module
Faulty coolant temperature sensor providing incorrect feedback to the control module
Software glitch or internal fault in the control module driving the pump

How to diagnose and fix it

Verify battery voltage and check all fuses related to the cooling pump circuit
Inspect the pump connector and wiring for corrosion, damage, or loose pins
Command the pump on with a scan tool and listen for operation; check for power and ground at the pump
Perform a voltage drop test on the pump power and ground circuits under load
Compare actual pump speed or current feedback with commanded values using live data
If electrical checks pass, remove the pump and inspect for mechanical binding or debris in the impeller
Replace the coolant pump if it fails to operate or is mechanically stuck, then clear codes and verify repair

What the coolant pump B code hides

A pump that runs quietly but draws excessive current can set this code without any visible overheating, so always check current draw against specifications.
Debris from a deteriorating coolant hose or failing water pump can lodge in the impeller and cause a stall condition that mimics an electrical failure.
The control module may set this code if the pump feedback signal is missing even when the pump is physically functional, so do not overlook wiring integrity.
On some vehicles, low coolant level or air pockets can cause the pump to cavitate and stall, triggering the code without a defective pump.
After replacing the pump, some systems require a bleed procedure or a scan tool activation to purge air and prevent recurrence of the code.

Can I keep driving with P2D05?

Do not continue driving with this code active, as a stalled coolant pump can quickly lead to overheating of the power electronics and cause expensive damage. If the vehicle must be moved, keep the drive short and monitor temperature closely, but it is safer to have it towed to a repair facility.

Tools that help

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