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P2600 OBD-II Trouble Code: Coolant Pump Control Circuit/Open

diagnostic check engine light

P2600 code definition

The P2600 trouble code detects an error with the auxiliary coolant pump control circuit.

What the P2600 code means

The P2600 code is a generic OBD-II trouble code that notes a circuit error with the auxiliary coolant pump. The coolant pump control circuit is closely monitored by the powertrain control module (PCM), and numerous other control modules, such as the transmission control module, fuel injection control module, and body control module. When the PCM or an accompanying control module detects a coolant pump control circuit malfunction, then the P2600 trouble code will be triggered.

What causes the P2600 code?

The P2600 trouble code is usually the result of a faulty coolant pump control relay. However, the code can also be caused by damaged electrical components (such as wires, connectors, fuses, and harnesses) in the controller area network (CAN) bus, a broken ground wire, or a loose control module ground strap. While rare, the code can also be caused by a malfunctioning PCM or CAN bus.

What are the symptoms of the P2600 code?

When the P2600 trouble code is detected, the check engine soon Warning Light will likely illuminate on the instrument panel. The vehicle may also experience a diminished heater efficiency, as well as an overheating engine.

How does a mechanic diagnose the P2600 code?

The P2600 code will be diagnosed with the help of a standard OBD-II trouble code scanner. A certified technician will look at the freeze frame data to assess the P2600 code, and to check for the presence of other trouble codes. If the mechanic notes that multiple trouble codes are present, then they will need to be addressed in the order in which they appear on the scanner. The trouble codes will then be reset, and the vehicle restarted, so the mechanic can see if the P2600 code remains detected. If not, then an intermittent error, or possibly an erroneous trigger is the likely cause of the code.

If the code remains detected, then the mechanic will visually inspect the electrical components in the CAN bus. If any fuses are blown, connectors are open or corroded, or wires are shorted, then they will need to be replaced. The ground wire and ground strap will then be tested, and finally the coolant pump control relay should be inspected.

If these inspections yield no results, then a specialized CAN scanner can be hooked up. This diagnostic scanner will help the mechanic inspect the control modules, and pinpoint where the issue is originating.

After any component is replaced, the mechanic will halt the inspection, reset the trouble codes, restart the vehicle, and check for the P2600 code. By doing this, the technician will be alerted as soon as the issue is resolved.

Common mistakes when diagnosing the P2600 code

The most commonly made errors when diagnosing the P2600 code come from a failure to properly comply with the OBD-II diagnosis protocol. Mechanics should follow the protocol step by step at all times, as this helps ensure thorough and efficient inspections, and avoid erroneous repairs.

It is very common for the P2600 code to be joined by numerous other trouble codes. These codes may be in response to a communication issue created by the P2600 code. If the codes are not addressed in the order in which they appear, unnecessary inspections and replacements may take place.

How serious is the P2600 code?

A vehicle with the P2600 trouble code will still be drivable, though the engine may overheat, which can cause damage. Because of this, the vehicle should be inspected and repaired as soon as the code is detected.

What repairs can fix the P2600 code?

Fixes for the P2600 trouble code are:

Additional comments for consideration regarding the P2600 code

It is very uncommon for the P2600 trouble code to signal a defective PCM or CAN bus, so all potential causes should be inspected before PCM or CAN bus failure is presumed. If either of these need to be replaced, they will also need to be reprogrammed.

Need help with a P2600 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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