P203B Diagnostic Trouble Code

P203B is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a P203B diagnostic trouble code may include:

The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly
Faulty or damaged wiring
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 :

A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Faulty IMRC actuator relay (if equipped)
Defective ECU strategies or components will prevent proper regeneration

Repair Processes :

Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. 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.

Process Tips

Diagnostic trouble code P203B 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 P203B.

Fortunately, P203B is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P203B Trouble Code For Specific Cars

P203B Diatto Type 20 Hydraulic Pump Relay Circuit Low
P203B Durant Star Immobilizer Code Not Programmed
P203B Adler 14 ABS Inlet Valve Coil RR Circuit Failure
P203B Fiat 501 Lamp Anti-Theft Indicator Circuit Open
P203B Mercedes-benz C Class Air Flow Blend Door Driver Circuit Failure
P203B Bizzarrini Gt Brake Switch Malfunction
P203B Bmw 535 CI Circuit Malfunction