P2603 Code - Coolant Pump 'A' Control Circuit High
Quick Answer
The diagnostic trouble code P2603 indicates an issue with the coolant pump 'A' control circuit being too high. Common causes include Faulty coolant pump, Damaged wiring or connectors in the coolant pump circuit, Malfunctioning coolant temperature sensor. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P2603 indicates Coolant Pump 'A' Control Circuit High.
- Common causes
- Common causes include Faulty coolant pump, Damaged wiring or connectors in the coolant pump circuit, Malfunctioning coolant temperature sensor.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P2603 Description
The diagnostic trouble code P2603 indicates an issue with the coolant pump 'A' control circuit being too high. In vehicles, the coolant pump is responsible for circulating coolant throughout the engine to maintain optimal operating temperature. When the control circuit for the coolant pump is registering a high voltage, it means that there is an electrical malfunction that is preventing the pump from functioning properly.
Common Causes of P2603
- Faulty coolant pump
- Damaged wiring or connectors in the coolant pump circuit
- Malfunctioning coolant temperature sensor
- Issues with the engine control module (ECM)
- Low coolant levels
Symptoms of P2603
- Engine overheating
- Engine running hot even at low speeds
- Coolant leaking from the pump area
- Engine misfires or stalling
- Reduced fuel efficiency
How to Fix P2603
- Begin by checking the coolant pump and associated wiring for any visible signs of damage or wear.
- Test the coolant temperature sensor to ensure it is functioning correctly.
- Use a multimeter to check the voltage in the coolant pump circuit and determine if it is too high.
- If the issue persists, consider replacing the coolant pump or repairing/replacing any damaged wiring or connectors.
- Clear the diagnostic trouble code and test drive the vehicle to ensure the issue has been resolved.
Cost to Fix P2603
The typical repair costs for resolving a coolant pump 'A' control circuit high issue can range from $200 to $600, including parts and labor. However, the specific diagnosis time and labor rates at auto repair shops can vary based on factors such as location, vehicle make and model, and engine type. It is advisable to check local rates for a more precise estimate.
Need more information about the P2603 code?
Need more information on how to fix the P2603 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P2603 code diagnosed by a professional: Find a repair shop in your area
Code P2603 Information for Specific Makes
- P2603 Buick — Auxiliary Coolant Pump Circuit High
- P2603 Cadillac — Auxiliary Coolant Pump Circuit High
- P2603 Chevrolet — Auxiliary Coolant Pump Circuit High
- P2603 Dodge — Coolant Pump 'A' Control Circuit High
- P2603 GMC — Auxiliary Coolant Pump Circuit High
Frequently Asked Questions about P2603 Code
No Frequently Asked Questions about P2603 Code found.
Discuss the causes and fixes for P2603 OBDII Code
Code P2603 comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.