U1779 Diagnostic Trouble Code

U1779 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 U1779 diagnostic trouble code may include:

If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Corroded or damaged connector
Reduction in engine performance, especially at low RPM levels
Diminished fuel efficiency

Possible Causes :

Faulty IMRC actuator/sensor
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

If all testing has passed so far yet you still have the same code, check your scan tool and see if it can open and close the IMRC valve. Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness.

Process Tips

Diagnostic trouble code U1779 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 U1779.

Fortunately, U1779 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U1779 Trouble Code For Specific Cars

U1779 Bizzarrini Manta Brake Switch Out Of Self Test Range
U1779 Porsche 965 Fuel level Sensor Circuit High Input
U1779 Bsa Fwd Cruise Control/Brake Switch A Circuit Malfunction
U1779 Buick 70 Cylinder 4 Injector Circuit Low
U1779 Ferrari 156 Injector Control Circuit
U1779 Ferrari 126 Injector Circuit Open / Shorted - Cylinder #6
U1779 Mercedes-benz 290 Air Bag Passenger Circuit Short To Ground