B2639 Alfa Romeo 156 Diagnostic Trouble Code

B2639 Alfa Romeo 156 code definition:
B2639 is a kind of OBD-II Diagnostic B-Body Diagnostic Trouble Code for Alfa Romeo 156.

B2639 Alfa Romeo 156 is triggered when the bank 1 camshaft position sensor doesn't match the signal from the crankshaft position sensor. 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 B2639 Alfa Romeo 156 diagnostic trouble code may include:

Faulty PCM
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Poor acceleration
Hesitation upon 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.
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.

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 :

Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. Look at the plug wires to make sure they are not burnt or laying on the exhaust. 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 B2639 Alfa Romeo 156 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 B2639 Alfa Romeo 156.

Fortunately, B2639 Alfa Romeo 156 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.