P2601 Code: Coolant Pump Control Circuit Range/Performance

What the P2601 code means

Many modern engines use electric coolant pumps, or mechanical pumps with a controlled clutch. The computer decides when to circulate coolant so the engine warms up sooner and so the turbo is cooled after you shut the engine off.

The computer watches the control circuit from its own driver transistor. The P2601 code reports that the component responds electrically but the result is not what is expected. Before you replace the component, check the fuse, relay, connector and wiring, which are the most common cause.

Some pumps talk to the computer with a PWM signal or over the LIN bus.

This kind of fault does not usually give itself up to a multimeter, because electrically everything looks right. You have to compare what the part says with reality: use a gauge, a thermometer or a tachometer, or command the component with the scan tool and see whether the physical result matches the command.

P2601 code symptoms

• Check engine light or another warning light on.
• Overheating of the engine or the turbo.

Likely causes of the P2601 code

1. Pump worn or with a damaged impeller. Measure its real flow or pressure.
2. Air in the cooling system. Bleed it following the manufacturer procedure.
3. Thermostat or circuit valves. Check them by commanding them with the scan tool.
4. Low coolant level. Check it with the engine cold.

How to diagnose the P2601 code step by step

1. Command the component with the scan tool and check whether it responds.
2. Check the fuse and relay. Measure voltage on both sides of the fuse and swap the relay with an identical one.
3. Measure the supply at the connector: battery voltage with the key on or when it is commanded.
4. Measure the component resistance and compare it with the manual, and check the insulation to ground too.
5. Check the control wire: continuity to the computer and no short circuits.

How to fix the P2601 code

• Repair the connector, the wiring or the supply.
• Replace the coolant pump if it does not respond with correct supply and command.
• Clear the codes and verify.

Technical reference data

• 12 V supply and PWM or LIN control.
• Approximate values only: check the manufacturer data for your vehicle.

Brand-specific notes

Air in the system is a common cause after any coolant service, so make sure the system was bled properly before you condemn the pump. The P2601 code is also a reason to check the coolant level with the engine cold.

P2601 on BMW

Common on BMW, where the main coolant pump is electric.

P2601 on Volkswagen and Audi

Common on these makes, where an auxiliary pump is used.

P2601 on Ford EcoBoost and Mercedes-Benz

Also common on Ford EcoBoost engines and on Mercedes-Benz.

Frequently asked questions about P2601