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 thinks the temperature sensor for the alternative fuel tank is reading a temperature that is too low. It's like when a thermometer says it's freezing outside when it's actually warm.
The P01AC code is triggered when the Engine Control Module (ECM) detects a low voltage signal from the alternative fuel tank temperature sensor, indicating a temperature reading that is lower than expected.
The alternative fuel tank temperature sensor monitors the temperature of the fuel in the alternative fuel tank. This sensor sends a voltage signal to the ECM, and if the signal voltage is too low, the ECM sets the P01AC code. This could be due to a faulty sensor, wiring issues, or a problem with the ECM.
• Check Engine Light is on
• Possible fuel efficiency issues
• Inaccurate fuel gauge readings
• Faulty alternative fuel tank temperature sensor
• Wiring issues such as shorts or open circuits
• Faulty ECM
ECM: Engine Control Module
OBD-II: On-Board Diagnostics II
• Use an OBD-II scanner to verify the P01AC code.
• Inspect the wiring and connectors for the temperature sensor.
• Test the sensor's resistance and voltage output.
• Replace the faulty temperature sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Chevrolet Volt
• Toyota Prius
• Nissan Leaf
• Regularly inspect and maintain the vehicle's wiring and connectors.
• Keep the fuel system clean and free of contaminants.
• Use quality fuel to prevent sensor damage.
Sensor Issue
• Have the vehicle inspected by a professional if the Check Engine Light is on.
• Avoid ignoring the issue to prevent potential fuel efficiency problems.
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
This code is typically associated with vehicles that use alternative fuels and have specific sensors for monitoring fuel temperature.
Moderate – Addressing this issue can prevent further fuel system problems.
Driving with an active Check Engine Light could lead to emissions test failures and potential fines.
• Engine at operating temperature
• Vehicle in a safe, stationary position
The alternative fuel tank temperature sensor is typically located on or near the alternative fuel tank.
Q: Can I drive with a P01AC code?
A: It's possible to drive, but it's best to address the issue soon to avoid potential fuel system problems.
Q: How do I reset the Check Engine Light after repairs?
A: Use an OBD-II scanner to clear the code after completing repairs.
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