Powertrain, generic (extended)

P2A66 Alternative Fuel Tank C Level Sensor Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2A66 says the tank C level signal is below its lower electrical bound. With voltage-output senders that typically comes from a signal wire grounded somewhere along its route, a sender shorted inside, or a missing supply to a ratiometric Hall module such as those Rochester builds for LPG vessels, which needs a few volts to produce any output. The display consequence is an empty or missing tank C, so a driver may refuel early or think the gas supply is shorter than it is. No manufacturer documents P2A66, and since the petrol code family covers only two senders, the nearest documented relative is the tank B case P2A61. Disconnecting the sender should move the reading; if it stays low, trace the short in the harness.

Likely causes

Tank C sender signal wire grounded
No supply voltage at a Hall-type sender
Tank C sender shorted internally

Symptoms

  • Check engine light
  • Tank C displayed as empty
  • Refuelling earlier than needed

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–700
Time0.5–3 h

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

Parts involved

alt fuel tank c level sensorwiring harnessafcm

Related codes

P2A64P2A67P2A65P2A61P01B1

References: law.cornell.edu, rochestersensors.com.