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 voltage of a part of the air conditioning system. It's like when a thermometer isn't working right and gives a wrong temperature reading.
The P1D59 code indicates that the voltage sensor for the A/C coolant heater's Phase W is not performing within the expected range.
The A/C Coolant Heater Phase W Voltage Sensor 'A' is responsible for monitoring the voltage levels in the A/C coolant heater circuit. When the sensor detects a voltage level that is outside the expected range, the Powertrain Control Module (PCM) triggers the P1D59 code.
• Check Engine Light is on
• A/C system not working properly
• Unusual noises from the A/C system
• Faulty A/C Coolant Heater Phase W Voltage Sensor
• Wiring issues in the sensor circuit
• Faulty PCM
PCM: Powertrain Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connections to the sensor.
• Test the sensor for proper operation.
• Replace the faulty A/C Coolant Heater Phase W Voltage Sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the PCM if necessary.
• OBD-II Scanner
• Multimeter
• Wrench set
$150 - $500
Moderate
• Honda Accord
• Honda Civic
• Acura MDX
• Regular maintenance of the A/C system
• Periodic inspection of electrical connections
• Routine diagnostic checks
Sensor Issue
• Have the vehicle inspected by a professional.
• Avoid using the A/C system until repaired.
Check with the vehicle manufacturer for warranty coverage on the A/C system components.
This code has been associated with issues in vehicles with advanced A/C systems, particularly in models with electric heaters.
Moderate – It is recommended to address this issue soon to prevent further A/C system problems.
Driving with a malfunctioning A/C system may not be safe in extreme weather conditions. Always ensure your vehicle's systems are functioning properly.
• Engine running
• A/C system activated
The A/C Coolant Heater Phase W Voltage Sensor is typically located near the A/C compressor or within the engine compartment.
Q: Can I drive with a P1D59 code?
A: While the vehicle may still be drivable, it's best to have it checked out to ensure the A/C system is functioning properly.
Q: How do I reset the check engine light after fixing the issue?
A: You can use an OBD-II scanner to clear the code, or the light may turn off after several driving cycles if the issue is resolved.
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