U0178 Diagnostic Trouble Code

U0178 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a U0178 diagnostic trouble code may include:

Misfire
Misfire
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Reduction in engine performance, especially at low RPM levels

Possible Causes :

Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. Use the DVOM to test resistance and continuity on all system circuits if actuator and sensor resistance levels are in compliance with manufacturer's specifications.

Process Tips

Diagnostic trouble code U0178 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before U0178.

Fortunately, U0178 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U0178 Trouble Code For Specific Cars

U0178 Scion Xd Injector Circuit / IDM Codes Not Updated
U0178 Nissan Otti Convertible Top Up/Down switch Fault
U0178 Rambler American Fuel Temperature Sensor B Circuit Range/Performance
U0178 Austin-healey 100 Aux A/C Control Switch Reference Circuit Short to Ground
U0178 Borgward Isabella Control Sleeve Sensor Malfunction
U0178 Volvo 1500 SCP (J1850) Invalid or Missing Data for Climate Control (HVAC)
U0178 Austin Mini Aux A/C Blower Speed 1 Circuit Failure