Powertrain, generic · Auxiliary emission controls

P0462 Fuel Level Sensor A Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

The fuel level sensor is a float on a resistor track in the tank unit. It is no emission part, but other monitors depend on it – the EVAP leak tests, for example, need at least 15 % fuel – so CARB requires it to be monitored and the usual exemption from the warning lamp does not apply. Low and high refer to the signal, not the fuel level: on GM a full tank is about 40 Ω and a low voltage, while Ford judges the resistance directly. P0462 means the signal is below its lower limit: GM below 10 % of the 5 V reference (100 of 125 samples, MIL after two trips), Saab 9-4X below 0.25 V for 5 s, Ford a resistance below 5 Ω for 30 s. Typical is a signal wire shorted to ground or a shorted sensor. The gauge sticks at one end and a substitute value is used.

Likely causes

Signal wire shorted to ground (chafed at tank or underbody)
Sensor shorted or damaged internally
Water or corrosion in the tank connector
Evaluating module faulty

Symptoms

  • Fuel gauge wrong, stuck or jumping
  • Range display and low-fuel warning wrong
  • Check engine light (depending on the maker)

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–600
Time0.5–3 h

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

Parts involved

fuel level sensor afuel tank unitsensor wiringengine control module

Related codes

P0460P0461P0463P0464P2067

References: gsi.ext.gm.com, gsi.ext.gm.com, fordservicecontent.com, saabwisonline.com.