Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer is saying that the electric pump that helps cool the engine is getting too much power.
The P2603 code indicates that the Powertrain Control Module (PCM) has detected a high voltage condition in the control circuit of the coolant pump 'A'. This could mean there's an issue with the wiring or the pump itself.
This diagnostic trouble code (DTC) is set when the PCM detects a higher than expected voltage in the control circuit of the auxiliary coolant pump 'A'. This could be due to a short circuit, a faulty pump, or an issue with the PCM.
• Check Engine Light illuminated
• Engine overheating
• Reduced engine performance
• Faulty coolant pump
• Short circuit in the wiring
• Faulty PCM
PCM: Powertrain Control Module
DTC: Diagnostic Trouble Code
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the coolant pump for proper operation.
• Replace the faulty coolant pump.
• Repair or replace damaged wiring or connectors.
• Replace the PCM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly inspect and maintain coolant system components.
• Ensure proper electrical connections.
• Use quality replacement parts.
Electrical Circuit Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional.
• Avoid driving the vehicle if it is overheating.
Repairs may be covered under the vehicle's powertrain warranty if applicable.
This code has been associated with issues in vehicles using electric coolant pumps, often due to electrical faults.
High – This issue can lead to engine overheating, which can cause severe engine damage.
Driving with an overheated engine can be dangerous and may lead to further damage.
• Engine at operating temperature
• Electrical system fully charged
The coolant pump is typically located near the front of the engine, often driven by the serpentine belt or electrically controlled.
Q: Can I drive with a P2603 code?
A: It's not recommended to drive with this code as it can lead to engine overheating.
Q: How do I reset the P2603 code?
A: The code can be reset with an OBD-II scanner after repairs are made, but it may reappear if the issue is not resolved.
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