U300C Diagnostic Trouble Code

U300C 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 U300C diagnostic trouble code may include:

Faulty PCM
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Poor acceleration
Rich or lean exhaust

Possible Causes :

The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Fuel with a large percentage of sulfur will clog the DPF quickly
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.

Repair Processes :

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. If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for.

Process Tips

Diagnostic trouble code U300C 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 U300C.

Fortunately, U300C is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U300C Trouble Code For Specific Cars

U300C Nissan Skyline Cruise Control On Signal Malfunction
U300C Ford Wind Motor # 1 Input Circuit Short to Gnd
U300C Bentley Speed Blend Door Failure
U300C Subaru H6 Left Rear Backup Lamp Circuit Short to Battery
U300C Studebaker Golden Hawk Lamp Turn Signal Right Circuit Open
U300C Daf 55 Gear Lever X Position Circuit Intermittent
U300C Ford Quadricycle Mirror Passenger Horizontal Switch Circuit Open