U278C Suzuki Wagon R Diagnostic Trouble Code

U278C Suzuki Wagon R code definition:
U278C is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code for Suzuki Wagon R.

U278C Suzuki Wagon R is described as Fuel Rail Pressure Sensor Circuit Malfunction. This code is strictly about the incoming signal from the FRP (fuel rail pressure) sensor falling below the calibrated limit for a certain period of time. If the car doesn't start, they will proceed by testing the voltage at the fuel pump connector and see if the fuel pump relay, fuse, and PCM circuitry should be inspected.

Symptoms

Symptoms of a U278C Suzuki Wagon R diagnostic trouble code may include:

Excessive exhaust leak
Hesitation upon acceleration
Malfunction Indicator Lamp (MIL) illuminated
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.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

Common Misdiagnoses

TP Sensor Learn Not Complete Problem
Low Coolant Circuit Problem
Cruise Control System - Vehicle Accel Too High Problem
TFP Valve Position Switch-Drive Without Drive Ratio Problem
Problem

Repair Processes :

Use the DVOM to test resistance and continuity on all system circuits if actuator and sensor resistance levels are in compliance with manufacturer's specifications. 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. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed.

Process Tips

Diagnostic trouble code U278C Suzuki Wagon R 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 U278C Suzuki Wagon R.

Fortunately, U278C Suzuki Wagon R is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.