U012B Mitsubishi L300 Diagnostic Trouble Code

U012B Mitsubishi L300 code definition:
U012B is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code for Mitsubishi L300.

U012B Mitsubishi L300 is defined as Camshaft Position Sensor A Circuit Low. This means the CMP (camshaft position) sensor circuit on engine bank 1 sends an irregular reading. Other symptoms that may indicate this problem are when the Check Engine Light illuminates and when there is a visible lack of engine power.

Symptoms

Symptoms of a U012B Mitsubishi L300 diagnostic trouble code may include:

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

Possible Causes :

Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
An air leak forward of the DPF will change the sensor readings resulting in the code
Faulty IMRC actuator relay (if equipped)

Common Misdiagnoses

Crankshaft Position Sensor Circuit Performance Problem
TP Sensor Learn Not Complete Problem
Low Coolant Circuit Problem
Cruise Control System - Vehicle Accel Too High Problem
Kick-Down Switch Failed Short Problem

Repair Processes :

Look at the plug wires to make sure they are not burnt or laying on the exhaust. If you find a related TSB, the information will often help in diagnosing the code in question as TSBs are crested from many thousands of repairs. 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 U012B Mitsubishi L300 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 U012B Mitsubishi L300.

Fortunately, U012B Mitsubishi L300 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.