P306C Fiat Croma Diagnostic Trouble Code

P306C Fiat Croma code definition:
P306C is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code for Fiat Croma.

P306C Fiat Croma is described as Oxygen Sensor Circuit No Activity Detected (Bank 1, Sensor 1). This means there's a problem in the front oxygen sensor on Bank 1, as the O2 sensor is inactive. The spark should have a light tan color. If the sensor probe comes with white and chalky parts, this means it has been lagging between switching phases, and should be replaced.

Symptoms

Symptoms of a P306C Fiat Croma diagnostic trouble code may include:

Carbon Buildup on O2 Sensor
Malfunction Indicator Lamp (MIL) illuminated
Hesitation upon acceleration
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

Fuel with a large percentage of sulfur will clog the DPF quickly
The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Some aftermarket accessories and performance modifications

Common Misdiagnoses

Exhaust Gas Recirculation System Valve 1 Problem
BBV Sensor Circuit Low Voltage Problem
Transmission Engaged At High Throttle Angle Problem
Cruise Inhibit Control Circuit Problem
TFP Valve Position Switch-Drive Without Drive Ratio Problem

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors.

Process Tips

Diagnostic trouble code P306C Fiat Croma 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 P306C Fiat Croma.

Fortunately, P306C Fiat Croma is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.