P2601

Symptoms

• Check engine light
• engine overheating (temperature gauge reading high)
• cabin heater blowing cold air
• especially at idle
• poor engine performance
• increased emissions.

Probable causes

• Failed electric coolant/water pump (seized motor or worn impeller preventing circulation)
• faulty coolant pump relay
• damaged wiring or corroded connectors in the pump control circuit
• air trapped in the cooling system from a leak or improper bleeding causing the pump to spin in air
• on some applications a failed Coolant Heat Storage (CHS) water pump or its relay
• rarely PCM failure.

Diagnostic steps

1. Connect an OBD-II scanner, confirm P2601 and check for related codes; review freeze frame data for the conditions when the fault set.
2. Inspect the coolant pump wiring, connectors and relay for damage, corrosion and loose connections - sources report connections and relays as the most common fault area, with pump failure second.
3. Check coolant level and look for leaks; bleed air from the cooling system per manufacturer procedure if aeration is suspected.
4. Test the coolant pump relay operation.
5. Test the coolant pump itself for proper operation (motor running, coolant actually circulating).
6. Repair wiring or replace the relay or pump as identified.
7. Suspect the PCM only after circuit, relay and pump all test good.
8. Do not continue driving with an overheating engine - sources warn continued operation risks head gasket or cylinder head damage.