P11B5 Diagnostic Trouble Code

P11B5 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 P11B5 diagnostic trouble code may include:

Fuel pressure too high
Diminished fuel efficiency
Rich or lean exhaust
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.
Faulty IMRC actuator relay (if equipped)

Repair Processes :

It should be pretty close to battery voltage (12 volts). If not, then this is the circuit that has the problem. 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. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code P11B5 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 P11B5.

Fortunately, P11B5 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P11B5 Trouble Code For Specific Cars

P11B5 Fiat 519 Lamp Backup Switch Input Circuit Short To Ground
P11B5 Lanchester Dauphin Speed Vehicle Signal Circuit Failure
P11B5 Nissan Moco Compressor Overtemp Fault
P11B5 Citroen 15cv Fan Secondary Low with Low Fan On
P11B5 Skoda Citigo Kick Down Switch Circuit Malfunction
P11B5 Duesenberg A Illuminated Entry Relay Short To Battery
P11B5 Plymouth Neon Evaporative Emission Control System Vent Control Circuit Open