P1B22 Mercedes-benz 400 Diagnostic Trouble Code

P1B22 Mercedes-benz 400 code definition:
P1B22 is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code for Mercedes-benz 400.

P1B22 Mercedes-benz 400 is described as Oxygen Sensor Circuit No Activity Detected (Bank 1, Sensor 1). This means there's a problem in the front oxygen sensor on Bank 1, as the O2 sensor is inactive. There are two wires dedicated for each coil; one is battery feed which usually comes from the distribution center, and the other one for the coil driver circuit from the PCM. The PCM grounds or ungrounds the circuit to activate or deactivate the coil.

Symptoms

Symptoms of a P1B22 Mercedes-benz 400 diagnostic trouble code may include:

Cherry red hot catalytic converter
Poor acceleration
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Rich or lean exhaust

Possible Causes :

Faulty IMRC actuator relay (if equipped)
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
An air leak forward of the DPF will change the sensor readings resulting in the code

Common Misdiagnoses

Control Module Throttle Actuator Position Performance Problem
Air Conditioning (A/C) Clutch Feedback Circuit High Voltage Problem
Cruise Vehicle Speed/Set Speed Difference Too High Problem
Kick-Down Switch Failed Short Problem
Park/Neutral Postion (PNP) Switch Circuit Engine Torque Signal Circuit Problem

Repair Processes :

It should be pretty close to battery voltage (12 volts). If not, then this is the circuit that has the problem. 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 P1B22 Mercedes-benz 400 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 P1B22 Mercedes-benz 400.

Fortunately, P1B22 Mercedes-benz 400 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.