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 sensor that measures the electric current in a part of the air conditioning system. It's like a thermometer that says the temperature is way too high when it's not supposed to be.
The P1D4F code is triggered when the powertrain control module (PCM) detects an unusually high voltage signal from the A/C coolant heater phase W current sensor circuit.
The A/C coolant heater phase W current sensor is responsible for monitoring the current flow through the phase W circuit of the A/C coolant heater. If the sensor detects a voltage level that is higher than the expected range, it sends a signal to the PCM, which then triggers the P1D4F code.
• Check Engine Light is on
• A/C system not functioning properly
• Reduced heating or cooling efficiency
• Faulty A/C coolant heater phase W current sensor
• Damaged or corroded wiring or connectors
• PCM malfunction
PCM: Powertrain Control Module
A/C: Air Conditioning
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the A/C coolant heater phase W current sensor for proper operation.
• Replace the faulty A/C coolant heater phase W current sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the PCM if necessary.
• OBD-II scanner
• Multimeter
• Screwdrivers
$150 - $400
Moderate
• Honda Accord Hybrid
• Acura MDX Hybrid
• Honda Clarity
• Regular inspection of A/C system components
• Ensure proper maintenance of electrical connections
• Avoid overloading the A/C system
Sensor Issue
• Have the vehicle inspected by a professional mechanic.
• Avoid using the A/C system until the issue is resolved.
Check with your vehicle manufacturer for warranty coverage on the A/C system components.
This code is more common in hybrid vehicles where the A/C system is integrated with the vehicle's electrical system.
Moderate – The vehicle can still be driven, but the A/C system may not work properly.
Operating a vehicle with a malfunctioning A/C system can lead to discomfort and reduced visibility due to fogging.
• Engine running
• A/C system activated
The A/C coolant heater phase W current sensor is typically located near the A/C compressor or integrated within the A/C control module.
Q: Can I drive with the P1D4F code?
A: Yes, but the A/C system may not work properly, which could lead to discomfort.
Q: Does this code affect fuel efficiency?
A: It may slightly affect fuel efficiency if the A/C system is not operating optimally.
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