Powertrain, generic · Fuel and air metering

P01AE Alternative Fuel Tank Temperature Sensor Circuit Intermittent/Erratic

Check engine lightUsually off
EmissionsRelevant
Drive cycleRequired
Limp modePossible

These codes only apply to vehicles with a gaseous alternative fuel – compressed natural gas (CNG) or LPG – as bi-fuel models alongside petrol or as dedicated gas engines; on bi-fuel vehicles a fault usually blocks gas operation and the vehicle runs on petrol. The tank temperature sensor is an NTC thermistor: with CNG there is no float, so the gas level is calculated from tank pressure and tank temperature (GM: full at about 3600 psi at 21 °C, empty at about 400–500 psi). On GM's 2015 Impala Bi-Fuel the sensor is built into the tank and cannot be replaced separately. P01AE covers brief dropouts or jumps in the signal, typically a loose contact or a harness chafing along the underbody. The Roush propane conversion for Ford E- and F-series trucks (2016–2018) uses this code for its combined tank pressure/temperature sensor (NTC, 8–12 kΩ at 20–30 °C), with the signal travelling via its own module and CAN to the engine module; according to its table the code does not light the MIL.

Likely causes

Loose contact or corrosion at the connector
Harness chafed along the gas line or underbody
Sensor unstable internally

Symptoms

  • Stored fault code (warning light depending on system)
  • Gas level display wrong
  • Gas operation blocked, switch to petrol

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–3,000
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

alternative fuel tank temperature sensorsensor wiring

Related codes

P01AAP01ABP01ACP01AD

References: law.cornell.edu, roushcleantech.com, static.nhtsa.gov.