P2066: How to Diagnose & Fix — Fuel Level Sensor "B" Circuit Range/Performance

The C6 Corvette carries its fuel in two saddle-shaped tanks that straddle the driveline tunnel, each with its own level sender. The left tank holds the fuel pump module and its sender is Fuel Level Sensor 'A'; the right tank has a passive sender, Fuel Level Sensor 'B', and its fuel is siphoned across to the pump side. Because the right tank is drawn down first, the 'B' float and its resistor card spend much of the car's life sitting in vapor rather than submerged in gasoline, and owners report the code appearing most often when the car is driven hard on less than half a tank. That dry-wiping is what kills them: the wiper arm scrubs a dead spot or a high-resistance band into the resistive card, so the sender's output stops tracking fuel actually being burned. The PCM compares the two senders and the fuel actually consumed, and when the 'B' signal is present but not credible it sets P2066 rather than a hard open/short code such as P2067 or P2068. Owners typically describe a gauge that reads correctly on a fresh fill, then hangs at a fixed value for many miles before dropping abruptly, a Driver Information Center range-to-empty figure that goes nonsensical, and in some cases a gauge the cluster disables outright. The condition is not mechanically dangerous, but it strands owners who trust the gauge, and a stored MIL will block emissions readiness. Note that P2066 on this platform can also be provoked by a weak siphon jet pump that leaves the right tank unequally full, so the fuel level of both sides should be compared before condemning the sender.

The Chrysler LX/LD rear-drive cars use a saddle-shaped fuel tank that straddles the driveshaft, so a single sender cannot measure the whole tank. Fuel Level Sensor 1 lives on the primary (driver's) side with the electric pump module; Fuel Level Sensor 2 - the 'B' sensor in generic OBD-II terms - measures the secondary (passenger) lobe and is fed by a jet-pump siphon that transfers fuel across to the pump side. Both senders are read by the cluster/CCN and the fuel level data is then bussed to the PCM. Two things go wrong on the secondary side. The sender's resistive card wears or becomes contaminated so the float arm reads a fixed value, and the siphon jet pump can weaken or clog so the secondary lobe genuinely does not drain at the expected rate. Either way the module sees a fuel-level signal that is present but not credible against fuel consumed, and stores P2066 instead of the circuit-low or circuit-high codes. The classic owner complaint is a gauge that freezes somewhere between half and three-quarters and stays there for a hundred miles or more, then falls off a cliff, with range-to-empty and the low-fuel light never catching up. Because the same tank architecture is used across the platform, a Charger diagnosis translates directly to a Chrysler 300 or a Dodge Challenger.

The in-tank fuel-level sender's resistive card wears, causing the fuel gauge to read inaccurately — stuck on Empty or Full, bouncing/fluctuating, or dropping to E with a false low-fuel warning. The sender is integral to the fuel pump module, so a worn card typically means dropping the tank. It is a well-known GM truck problem; on high-mileage trucks technicians recommend replacing the complete fuel pump module rather than just the sender.

AWD Outlander Sport models use a two-lobe fuel tank shaped around the rear driveline, with a main sending unit and a separate sub sending unit measuring the second lobe. Mitsubishi's ECM does not simply watch the sub sender's voltage - it runs a consumption rationality test. Mitsubishi's published service data for this generation sets DTC P2066 when fuel consumption calculated from injector operation reaches 10 litres (2.6 gallons) while the level derived from the sub fuel level sensor has changed by less than 2 litres (0.5 gallon), or when the sub sender's resistance is 13 ohms or below or 70 ohms or above (earlier calibrations used a 30-litre consumption threshold). NHTSA recall 13V112000 documents the manufacturing defect behind this on 2013 AWD cars: certain Outlander Sport AWD vehicles manufactured June 11 through December 11, 2012 were built without the fuel sending unit harness for the sub sending unit, producing a false fuel tank level reading. With the sub sender never reporting a changing level, the gauge shows far more fuel than the tank holds, and the ECM's rationality monitor flags the implausible sub-sender data. The real-world consequence is the serious one for this code family: the driver may believe fuel remains when the tank is empty, and the engine stalls while driving. Outside the recall population the same monitor is set by an aged or contaminated sub level sensor, a corroded sub-sender connector, or a failed fuel pump module assembly.