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 the fluid used to clean the exhaust. It's like when a heater in a room doesn't work right because of an electrical issue.
The P248D code indicates that the vehicle's computer has detected a high voltage condition in the reductant heater B sense circuit.
The reductant heater is part of the vehicle's Selective Catalytic Reduction (SCR) system, which reduces emissions. Heater B is one of the components responsible for warming the diesel exhaust fluid (DEF) to ensure it flows properly. A high voltage reading in the sense circuit suggests a possible open circuit or a faulty sensor.
• Check Engine Light illuminated
• Possible reduction in engine performance
• Increased emissions
• Faulty reductant heater B
• Open or shorted reductant heater B circuit
• Poor electrical connection in the reductant heater B circuit
Reductant: A substance used in the SCR system to reduce emissions.
SCR: Selective Catalytic Reduction, a system that reduces nitrogen oxide emissions in diesel engines.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for the reductant heater B.
• Test the resistance of the reductant heater B.
• Repair or replace damaged wiring or connectors.
• Replace the reductant heater B if faulty.
• Clear the code and test drive to ensure the issue is resolved.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Ford F-250
• Chevrolet Silverado
• Ram 2500
• Regularly inspect wiring and connectors for damage.
• Ensure proper maintenance of the SCR system.
• Use high-quality diesel exhaust fluid.
Sensor Issue
• Avoid ignoring the check engine light.
• Have the vehicle inspected by a professional if unsure.
• Regularly maintain the vehicle's emission system.
Check with the vehicle manufacturer for warranty coverage on emission-related components.
This code has been more common in vehicles with advanced emission control systems, particularly in diesel engines.
Moderate – While the vehicle may still be drivable, it can lead to increased emissions and potential engine performance issues.
Driving with a malfunctioning emission system can lead to legal penalties and increased environmental impact.
• Engine at operating temperature
• Vehicle in a safe and stationary position
The reductant heater is typically located near the DEF tank or along the DEF line.
Q: Can I drive with a P248D code?
A: While you may be able to drive, it's not recommended due to potential increased emissions and engine performance issues.
Q: What does the reductant heater do?
A: It warms the diesel exhaust fluid to ensure it flows properly and helps reduce emissions.
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