U1278 Mitsubishi Galant Diagnostic Trouble Code

U1278 Mitsubishi Galant code definition:
U1278 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code for Mitsubishi Galant.

U1278 Mitsubishi Galant or the Evaporative Emission Control System Incorrect Purge Flow is the set whenever the computer sees that there is a problem with the flow coming from the purge valve or the purge flow is not enough within the EVAP system. 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 U1278 Mitsubishi Galant diagnostic trouble code may include:

Fuel pressure too low
Rich or lean exhaust
Diminished fuel efficiency
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

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

Common Misdiagnoses

Vehicle Speed Output Circuit Problem
Cruise Control Servo Indicates Low Problem
A/C System High Pressure High Temperature Problem
PCM Stack Overrun Problem
Transmission Control Module Reprogrammable Memory Problem

Repair Processes :

You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data. 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.

Process Tips

Diagnostic trouble code U1278 Mitsubishi Galant 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 U1278 Mitsubishi Galant.

Fortunately, U1278 Mitsubishi Galant is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.