Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer is saying that a sensor that checks the electricity flowing through a part of the car isn't working right. It's like when a toy's battery meter says the battery is full, but the toy doesn't work.
The code indicates that the sensor measuring the current in the DC/DC converter circuit is reporting a value that is lower than expected, which may not be accurate.
The P1C77 code is triggered when the Universal Charger Extension Control Module detects an implausibly low current reading from the high voltage current sensor in the DC/DC converter circuit. This could indicate a fault in the sensor, wiring, or the module itself.
• Check engine light is on
• Charging system malfunction warning
• Reduced charging efficiency
• Faulty high voltage current sensor
• Wiring issues or poor connections
• Faulty Universal Charger Extension Control Module
DC/DC Converter: A device that converts direct current (DC) from one voltage level to another.
Current Sensor: A device that measures the flow of electric current in a circuit.
• Perform a visual inspection of the wiring and connections related to the DC/DC converter and current sensor.
• Use a multimeter to check the current sensor's output and compare it to specifications.
• Test the Universal Charger Extension Control Module for faults.
• Repair or replace faulty wiring or connectors.
• Replace the high voltage current sensor if it's defective.
• Replace the Universal Charger Extension Control Module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$200 - $600
Moderate
• Chevrolet Volt
• Nissan Leaf
• Toyota Prius
• Regularly inspect electrical connections for corrosion or damage.
• Ensure the vehicle's charging system is maintained according to the manufacturer's schedule.
• Avoid excessive exposure to moisture which can affect electrical components.
Sensor Issue
• Have the vehicle inspected by a professional if the check engine light is on.
• Avoid using the vehicle's charging system until the issue is resolved.
Check with the vehicle manufacturer for warranty coverage on electrical components.
This code has been reported in vehicles with hybrid or electric powertrains, indicating a common issue with the DC/DC converter systems.
Moderate – While the vehicle may still operate, the charging system's efficiency could be compromised.
Driving with an unresolved electrical issue may lead to further damage or reduced vehicle performance.
• Vehicle in 'On' position
• Charging system active
The DC/DC converter and high voltage current sensor are typically located near the vehicle's battery or charging system components.
Q: Can I drive my car with a P1C77 code?
A: It's not recommended as it may affect the charging system's efficiency and could lead to further issues.
Q: How can I reset the P1C77 code?
A: You can try using an OBD-II scanner to clear the code, but if the issue persists, it will likely return.
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