P128A Diagnostic Trouble Code

P128A 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 P128A diagnostic trouble code may include:

Lack of power
Faulty O2 Sensor
Poor acceleration
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on 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.
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.

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 P128A 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 P128A.

Fortunately, P128A is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P128A Trouble Code For Specific Cars

P128A Tata Nano Mirror Passenger Vertical Feedback Potentiometer Circuit Short to Ground
P128A Lada 2110 Shift Solenoid A Malfunction
P128A Peugeot Asphalte Electronic Throttle Monitor Cruise Disable
P128A Citroen Axel Four Wheel Drive (4WD) Switch Circuit Low
P128A Lincoln Navigator Throttle/Pedal Position Sensor/Switch A Circuit Low Input
P128A Bmw M3 Clutch Pedal Switch A Circuit High
P128A Ducati Monster 797 Illuminated Entry Input Short Circuit To Battery