C3791 Ac 427 Diagnostic Trouble Code

C3791 Ac 427 code definition:
C3791 is a kind of OBD-II Diagnostic C-Chassis Diagnostic Trouble Code for Ac 427.

C3791 Ac 427 is defined as Ignition Coil B Primary/Secondary Circuit Malfunction.This code is a generic trouble code, meaning it applies to all vehicles equipped with OBD-II tool, or vehicles made since 1996 up to present. So if the problem persists despite of your diagnosis, then you should never hesitate to take your vehicle to your dealer or to a qualified mechanic.

Symptoms

Symptoms of a C3791 Ac 427 diagnostic trouble code may include:

Fuel pressure too high
Diminished fuel efficiency
Rich or lean exhaust
Reduction in engine performance, especially at low RPM levels

Possible Causes :

Dirty air cleaner element Damaged DPF
A plugged converter will cause of host of driveability problems as well as set this code. A severely plugged converter will result in the inability to increase rpm when under load. Look for a code such as P0421 -- catalytic converter efficiency below threshold if the converter indicating a faulty converter.
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 :

Oxygen sensors signal the engine management computer the amount of oxygen present in the exhaust, which is used in determining and controlling the fuel ratio. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data. 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 C3791 Ac 427 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 C3791 Ac 427.

Fortunately, C3791 Ac 427 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.