P0462

P0462 indicates the fuel level sensor signal voltage has dropped below the PCM's low threshold, typically under 0.15 to 0.25 volts, for longer than the calibrated window (often 30 seconds continuous). The signal wire is either shorted to ground, the sender is open at its high-resistance end, or the float is mechanically stuck at empty. Cheapest-first: back-probe the sensor signal pin at the tank-top connector with the key on and compare to the PCM reading on a scan tool. If the scan tool shows 0.0 volts but your meter reads a normal 1.5 to 4.0 volts at the connector, the wire between the connector and the PCM is shorted to ground (look for rub-throughs at body-to-frame transitions). If both read near zero, unplug the sender and check resistance across its terminals; an open card reads infinite, a shorted float reads near 0 ohms regardless of position. Expensive misdiagnosis: replacing the PCM for a chafed harness, or condemning a good sender when the actual fault is a corroded ground splice shared with the EVAP vent solenoid.

Vehicle-specific patterns: 2005-2010 Jeep Grand Cherokee WK has a known signal wire chafe point where the rear body harness crosses the unibody rail above the tank, often triggered after a tank drop for pump service. 2001-2007 Chrysler Town & Country and Dodge Caravan saddle-tank vans short the secondary float wire to the transfer pump housing when the rubber grommet on top of the tank deteriorates. 2007-2014 Chevrolet Tahoe and Suburban develop a corroded C305 body connector under the driver seat that drops level-sensor signal to ground after road salt intrusion. 2004-2009 Toyota Prius (NHW20) sees the level sensor wire pinched by the rear seat-belt buckle bolt during interior service. Estimated repair: $120 to $560.