Lean fuel condition at high load (open loop)
Code 0174
Component: Fuel System
Fault: Lean fuel condition
Condition: Fuel inlet screen/filter plugged, low
pressure at high pressure fuel line, TPS
malfunction, shorted connection or faulty
sensor.
Conclusion: TPS Learn Incorrect
● Lean condition (check oxygen sensor
signal with VOA and see Oxygen
Sensor).
Engine Wiring Harness Related
● Pin circuit wiring or connectors.
ECU pin Black 10, 12, 16 and 17.
Low Fuel Pressure
● Plugged filters.
● Bad lift pump.
Oxygen Sensor Related
● Sensor connector or wiring problem.
● Exhaust leak.
● Poor ground.
Poor system ground from ECU to engine,
causing rich running while indicating lean.
Fuel pump module connection. See Fuel components