U017B Diagnostic Trouble Code

U017B 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 U017B diagnostic trouble code may include:

Rich or lean exhaust
Fuel pressure too low
Engine surge
Diminished fuel efficiency

Possible Causes :

The Mass Airflow sensor is a hot wire that senses the volume of air entering the intake manifold. The computer uses this information to control fuel mixture.
Defective ECU strategies or components will prevent proper regeneration
Faulty IMRC actuator relay (if equipped)

Repair Processes :

Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. 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.

Process Tips

Diagnostic trouble code U017B 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 U017B.

Fortunately, U017B is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U017B Trouble Code For Specific Cars

U017B Hyundai Pony
U017B Maybach W3 Transmission Transfer Case Clockwise Shift Relay Coil Open Circuit
U017B Toyota Carina O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
U017B Bmw 120 Cam Calibration Fault
U017B Triumph 1800 Passenger's Front Seat Up Switch Circuit Short to Battery
U017B Gilbern Genie Oil Level Lamp Circuit Failure
U017B Dodge Lancer Ignition Key-In Circuit Failure