Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the part of the car that heats up a special fluid used to clean exhaust gases. It's like when your toaster doesn't heat up your bread properly.
The code indicates an issue with the performance of the heater driver for the reductant system, which is responsible for heating the diesel exhaust fluid (DEF) to ensure it works properly.
The reductant heater is part of the Selective Catalytic Reduction (SCR) system, which reduces harmful emissions in diesel engines. This code is set when the Engine Control Module (ECM) detects a performance issue with the heater driver circuit, which may affect the ability of the system to properly heat the DEF, potentially leading to increased emissions.
• Check Engine Light is on
• Possible reduction in engine performance
• Increased emissions
• Faulty reductant heater
• Open or shorted wiring in the heater circuit
• Faulty ECM or software issue
Reductant: A substance used to reduce emissions in diesel engines, often referring to diesel exhaust fluid (DEF).
SCR: Selective Catalytic Reduction, a system used to reduce nitrogen oxide emissions in diesel engines.
• Use a scan tool to verify the code and check for other related codes.
• Inspect the wiring and connectors for the reductant heater for damage or corrosion.
• Test the reductant heater for proper resistance and operation.
• Replace the faulty reductant heater.
• Repair or replace damaged wiring or connectors.
• Update or reprogram the ECM if necessary.
• OBD-II scan tool
• Multimeter
• Basic hand tools
$200 - $600
Moderate
• Ford F-Series
• Chevrolet Silverado
• Ram 2500
• Regularly inspect and maintain the exhaust system.
• Use high-quality diesel exhaust fluid.
• Keep the vehicle's software up to date.
Emission Control System Issue
• Have the vehicle inspected by a professional mechanic.
• Avoid ignoring the Check Engine Light as it may lead to more serious issues.
• Ensure the use of the correct type of diesel exhaust fluid.
Check with the vehicle manufacturer for warranty coverage on emission-related components.
This code has become more common with the increased use of SCR systems in diesel vehicles to meet stricter emission standards.
Moderate – Addressing this issue in a timely manner is important to avoid increased emissions and potential engine performance issues.
Operating a vehicle with this issue may lead to non-compliance with emission regulations.
• Engine at operating temperature
• Vehicle in a safe, stationary position
The reductant heater is typically located near the DEF tank or within the DEF delivery system.
Q: Can I drive with a P263D code?
A: While the vehicle may still be drivable, it's best to address the issue to avoid increased emissions and potential performance problems.
Q: What happens if I ignore this code?
A: Ignoring the code can lead to increased emissions, potential engine performance issues, and may result in failing an emissions test.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.