Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer has detected a problem with the power supply to a part that helps keep the car's pollution control system working in cold weather.
The P05ED code is triggered when the engine control module (ECM) detects an issue with the supply voltage to the reductant heater control module, which is responsible for heating the diesel exhaust fluid (DEF) to prevent it from freezing.
The reductant heater control module is part of the diesel exhaust aftertreatment system. It ensures that the DEF remains in a liquid state by heating it when necessary. If the supply voltage is outside the expected range, the ECM will set the P05ED code.
• Check Engine Light is on
• Poor engine performance
• Increased emissions
• Faulty reductant heater control module
• Poor electrical connection or damaged wiring
• Blown fuse or relay related to the heater circuit
DEF: Diesel Exhaust Fluid, a liquid used to reduce air pollution from diesel engines.
ECM: Engine Control Module, the computer that manages engine functions.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connections to the reductant heater control module.
• Check the fuses and relays related to the heater circuit.
• Repair or replace damaged wiring or connectors.
• Replace the reductant heater control module if faulty.
• Replace any blown fuses or faulty relays.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Ford F-250
• Chevrolet Silverado 2500
• Ram 2500
• Regularly inspect wiring and connectors for damage.
• Ensure fuses and relays are in good condition.
• Perform regular maintenance on the exhaust aftertreatment system.
Sensor Issue
• Do not ignore the Check Engine Light.
• Consult a professional mechanic if unsure about repairs.
Check with the vehicle manufacturer for specific warranty coverage on emissions-related components.
This code has been more common in colder climates where the DEF system is more likely to experience freezing conditions.
Moderate – Addressing this issue is important to maintain emissions compliance and engine performance.
Driving with a malfunctioning emissions system may violate local emissions laws and could lead to increased pollution.
• Cold weather conditions
• Engine running
The reductant heater control module is typically located near the DEF tank or integrated into the DEF pump assembly.
Q: Can I drive with a P05ED code?
A: While the vehicle may still be drivable, it is advisable to have it checked as soon as possible to avoid increased emissions and potential damage.
Q: What happens if I ignore this code?
A: Ignoring the code can lead to increased emissions, potential damage to the DEF system, and failing an emissions test.
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