P1B81 Hafei New Quing Diagnostic Trouble Code

P1B81 Hafei New Quing code definition:
P1B81 is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code for Hafei New Quing.

P1B81 Hafei New Quing is defined as Knock Sensor Circuit Range Performance (Bank 1 or Single Sensor). This refers to camshaft timing, which in this case is over-retarded. Other symptoms that may indicate this problem are when the Check Engine Light illuminates and when there is a visible lack of engine power.

Symptoms

Symptoms of a P1B81 Hafei New Quing diagnostic trouble code may include:

Rich or lean exhaust
Fuel pressure too low
Engine surge
Diminished fuel efficiency

Possible Causes :

The Mass Airflow sensor is a hot wire that senses the volume of air entering the intake manifold. The computer uses this information to control fuel mixture.
Defective ECU strategies or components will prevent proper regeneration
Faulty IMRC actuator relay (if equipped)

Common Misdiagnoses

Crankshaft Position Sensor Circuit Performance Problem
TP Sensor Learn Not Complete Problem
Low Coolant Circuit Problem
Cruise Control System - Vehicle Accel Too High Problem
Kick-Down Switch Failed Short Problem

Repair Processes :

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. 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 P1B81 Hafei New Quing 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 P1B81 Hafei New Quing.

Fortunately, P1B81 Hafei New Quing is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.