P0B84 Diagnostic Trouble Code

P0B84 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 P0B84 diagnostic trouble code may include:

Faulty or damaged wiring
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
Poor fuel economy
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.

Repair Processes :

If the engine displays a miss and there wasn't a code, determine which cylinder is misfiring. If the exhaust manifold is visible, spay or pour a small amount of water on each cylinder exhaust port. Water will evaporate immediately on good cylinders and slowly on the missing cylinder. If this can't be accomplished pull the plugs and check the condition. 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. If all testing has passed so far yet you still have the same code, check your scan tool and see if it can open and close the IMRC valve.

Process Tips

Diagnostic trouble code P0B84 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 P0B84.

Fortunately, P0B84 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P0B84 Trouble Code For Specific Cars

P0B84 Marmon V16 Transmission 4-Wheel Drive Mode Select Circuit Failure
P0B84 Ferrari 735 Intake Valve Control Solenoid Circuit Low (Bank 2)
P0B84 Rover 60 Ignition Coil C Primary Circuit Malfunction
P0B84 Daihatsu Micros Generator Field "F" Control Circuit Malfunction
P0B84 Lincoln 47 Hp Throttle Position (TP) Sensor Circuit Intermittent High Voltage
P0B84 Autobianchi Bianchina Aux Heater Coolant Sensor Circuit Short to Ground
P0B84 Tvr 3000 Port Air Relief Circuit Malfunction