P120A Diagnostic Trouble Code

P120A 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 P120A diagnostic trouble code may include:

Excessive exhaust leak
Hesitation upon acceleration
Malfunction Indicator Lamp (MIL) illuminated
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)
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

Repair Processes :

Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. Pull the connectors apart and carefully look at the terminals (the metal parts) inside the 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. 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.

Process Tips

Diagnostic trouble code P120A 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 P120A.

Fortunately, P120A is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P120A Trouble Code For Specific Cars

P120A Proton Inspira Fuel Shut Off Solenoid Malfunction
P120A Datsun On-do HO2S Heater Control Circuit (Bank 2 Sensor 2)
P120A Talbot 2500 Mirror Passenger Horizontal Feedback Potentiometer Circuit Open
P120A Mitsubishi Grandis Autolamp On Circuit Failure
P120A Kia Visto Servo Motor Defrost Circuit Failure
P120A Ford Ikon Mirror Driver Memory Position Error
P120A Lamborghini 400 Shift Solenoid E Stuck On