OBD Guide

P01AC

Alternative Fuel Tank Temperature Sensor Circuit Low

P01AC is an OBD-II diagnostic trouble code meaning: Alternative Fuel Tank Temperature Sensor Circuit Low. Common causes: sensor wire short circuit to ground, temperature sensor circuit open. Estimated repair cost: $22–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$22–89 (est.)

Symptoms

  • Inability to start on alternative fuel
  • Automatic switching to main fuel
  • Check Engine Light Illuminates
  • Increased fuel consumption
  • Unstable cold start

Causes

  • Sensor wire short circuit to ground
  • Temperature sensor circuit open
  • Faulty tank temperature sensor
  • Oxidation or damage to the sensor connector
  • ECU malfunction (rare)

How to Fix

  1. Read error codes and record data in case of failure
  2. Check the voltage at the sensor connector (normal 4.5–5 V)
  3. Check the wiring harness for breaks and short circuits
  4. Measure the sensor resistance and compare with the norm
  5. Clean the sensor connector from oxidation
  6. If necessary, replace the alternative fuel tank temperature sensor

Related codes

Error P01AC by Vehicle Brand

FAQ

What does the P01AC code mean?

P01AC is an OBD-II diagnostic trouble code that indicates: Alternative Fuel Tank Temperature Sensor Circuit Low

What causes a P01AC error code?

The most common causes of P01AC include: Sensor wire short circuit to ground; Temperature sensor circuit open; Faulty tank temperature sensor; Oxidation or damage to the sensor connector.

How do I fix a P01AC diagnostic trouble code?

To fix P01AC: Read error codes and record data in case of failure. Check the voltage at the sensor connector (normal 4.5–5 V). Check the wiring harness for breaks and short circuits. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P01AC?

Yes, but get it checked soon

How much does it cost to fix P01AC?

The estimated repair cost for P01AC is $22–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat