P0178 P0178 code definition Fuel Composition Sensor Circuit Low Input What the P0178 code means P0178 is a generic OBD-II code indicating that the diesel fuel sensor is giving a low input, which could be from an open circuit in...
Hi there. Some additional diagnostic tests will be necessary to identify the problem. The P1078 (https://www.yourmechanic.com/article/p0178-obd-ii-trouble-code-fuel-composition-sensor-circuit-low-input-by-jay) testing diagrams show that there are possible issues with a solenoid valve, a sensor, a vacuum leak, or an electrical issue. A certified mechanic...
