P2DFA: Coolant Pump E Supply Voltage Circuit

What it means

Coolant pump E reports a supply voltage circuit condition. Coolant circulation through the affected loop cannot be commanded reliably.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Coolant pump E needs a stable supply voltage to circulate coolant through its assigned loop. The controller monitors the electrical supply to that pump and sets this code when the supply circuit is outside its expected condition. A wiring, connection, power source, pump, or driver problem can interrupt reliable operation.

Common causes

Most likely first.

1. Pump motor or driver fault
2. Wiring or connector fault

Symptoms

• Check-engine light
• Coolant temperature warning or rising temperature gauge
• Reduced engine power

How to diagnose it

1. Review freeze-frame data and live coolant temperatures to determine whether pump E lost supply as the loop warmed.
2. With the engine cool, inspect pump E's power connector, fuse or circuit protection, and harness for looseness, corrosion, or damage.
3. Check the relevant power and ground paths using the vehicle wiring diagram, looking for opens, shorts, or poor connections.
4. Measure supply voltage at the pump while it is commanded and compare the result with the manufacturer's specification.
5. Use a scan tool to command pump E and check whether the supply remains stable as the pump operates.
6. If the supply circuit is sound, test the pump motor and driver for an internal fault.

Common fixes

• Secure or replace damaged pump E power and ground connections.
• Repair an open or shorted wire in the supply circuit.
• Replace a failed pump E if it draws or responds abnormally with correct supply.
• Repair a faulty pump driver or power feed if testing identifies it as the source.

Can I keep driving?

If the temperature gauge rises or a coolant warning comes on, stop safely and switch off the engine because pump E may not be receiving power. With normal temperature, minimize driving and monitor the gauge until the supply fault is fixed.