P26D6: Engine Coolant Pump Clutch Control Circuit / Open

What it means

The mechanical clutch on a belt-driven coolant pump (used to disengage the pump for fast warm-up) cannot be driven. Pump always engaged so warm-up takes longer.

At a glance

• Usually lights the check-engine light

How it works

On systems with a belt-driven coolant pump clutch, the clutch solenoid controls whether the pump is engaged. P26D6 indicates an open in the clutch control circuit, such as an open solenoid winding or broken wire, so the clutch may not respond to commands.

Common causes

Most likely first.

1. Open coil in clutch solenoid
2. Broken control wire

Symptoms

• Check-engine light may be on
• Engine may take longer to warm up
• Fuel economy may decrease slightly

How to diagnose it

1. Record freeze-frame data and check live clutch command and any available feedback to confirm when the open-circuit fault is detected.
2. Inspect the clutch solenoid connector and control harness for broken wires, corrosion, loose terminals, or damage near moving belts.
3. Check the clutch control fuse and verify the circuit has the expected supply and ground paths using the wiring diagram.
4. Test solenoid winding continuity against the manufacturer's specification to determine whether the coil is open.
5. If the winding is sound, trace control-wire continuity between the module and clutch and check for an open at the connectors.

Common fixes

• Repair a broken or damaged clutch control wire.
• Clean or repair loose or corroded clutch-solenoid connector terminals.
• Replace the clutch solenoid if its winding is open.
• Replace a failed fuse after identifying and correcting the cause.

Can I keep driving?

If the pump remains engaged, warm-up may take longer and fuel economy may worsen; monitor engine temperature and avoid driving if it rises or a cooling warning appears. Stop safely if the engine overheats.