P1B51 Diagnostic Trouble Code

P1B51 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 P1B51 diagnostic trouble code may include:

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

Repair Processes :

Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. Now, clear the codes and test-drive the vehicle to see if the code is reset.

Process Tips

Diagnostic trouble code P1B51 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 P1B51.

Fortunately, P1B51 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P1B51 Trouble Code For Specific Cars

P1B51 Ford Transit Mirror Switch Reference Voltage Positive Common Open Circuit
P1B51 Dagmar 6 Gear Shift Forward Actuator Circuit / Open [forward motion, odd gears, 1,3,5]
P1B51 Lexus Rx TFP Valve Position Switch Circuit/ Transmission 4-Wheel Drive Low Indicator Short Circuit To Battery
P1B51 Seat 1400 Injector Circuit Malfunction - Cylinder 3
P1B51 Alpine A108 Air Bag Memory Clear Circuit Short To Ground
P1B51 Ballot 2-litre B Camshaft Position - Actuator Circuit (Bank1)
P1B51 Honda Fuya PRNDL Reverse Input Short To Battery