OBD-II Generic Error Code P2602: How to Fix It

Q: Can I drive my car with a P2602 code?

It is not recommended. The P2602 code means the auxiliary coolant pump circuit is not functioning correctly, which can reduce your engine's cooling capacity. Driving with a compromised cooling system risks engine overheating, which can cause serious and expensive internal damage such as a blown head gasket or warped cylinder head. Address this code as soon as possible, and avoid driving if your temperature gauge rises above normal.

Q: What causes the P2602 code?

The most common causes of P2602 are a failed or seized auxiliary electric coolant pump, a faulty coolant pump relay, corroded or damaged wiring in the coolant pump control circuit, a blown fuse in the coolant pump circuit, or — less commonly — a fault in the ECM's output driver for the coolant pump. Low voltage on the control circuit wire is the defining symptom the ECM detects to set this code.

Q: How much does it cost to fix a P2602 code?

Repair costs vary depending on the root cause. Replacing a relay is usually under $20 and takes minutes. Replacing a fuse costs only a few dollars. A new auxiliary electric coolant pump typically costs between $50 and $250 for the part, plus one to two hours of labor at a shop. Wiring repairs vary widely based on the extent of damage. ECM replacement is the most expensive option, potentially ranging from $300 to over $1,000 including programming, and should only be considered after all other causes are ruled out.

Q: Is P2602 the same as a water pump failure?

Not exactly. P2602 specifically refers to the auxiliary electric coolant pump control circuit, not the main mechanical water pump driven by the engine's belt or timing chain. Many modern vehicles have both — the main water pump for primary coolant circulation and a secondary electric pump used for hybrid systems, turbo cooling, or cabin heating. P2602 targets the electric auxiliary pump circuit. If your vehicle has only one coolant pump and it is electric, then yes, this code is directly related to that pump.

Q: Will the P2602 code clear itself after fixing the problem?

The code will not clear itself automatically right away. Even after the underlying fault is repaired, the P2602 code will remain stored in the ECM until it is manually cleared using an OBD2 scanner, or until the vehicle completes a set number of drive cycles without the fault recurring (which varies by manufacturer). For best results, use an OBD2 scanner to clear the code after the repair, then test drive to confirm it does not return.

Abstract

The P2602 error code means your vehicle's engine control module (ECM) has detected a low voltage signal in the coolant pump control circuit. This typically points to a wiring fault, a failed coolant pump relay, or a defective auxiliary electric coolant pump. Because this code directly relates to your engine's cooling system, it carries medium severity — ignoring it can lead to engine overheating and costly damage.