P2604 Bmw 420 Diagnostic Trouble Code

P2604 Bmw 420 code definition:
P2604 is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code for Bmw 420.

P2604 Bmw 420 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. This is because the barometric pressure sensor is part of the MAF sensor. Sometimes, the MAF's sensing wire can accumulate and get covered with dirt, dust and/or oil residue, which can also lead to the error code.

Symptoms

Symptoms of a P2604 Bmw 420 diagnostic trouble code may include:

Excessive exhaust leak
Hesitation upon acceleration
Malfunction Indicator Lamp (MIL) illuminated
Rich or lean exhaust

Possible Causes :

Faulty IMRC actuator relay (if equipped)
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

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 :

Now, clear the codes and test-drive the vehicle to see if the code is reset. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground. 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 P2604 Bmw 420 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 P2604 Bmw 420.

Fortunately, P2604 Bmw 420 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.