B3021 Mazda Millenia OBD Code

OBD/2 B3021 error code description and symptoms.

HO2S Sensor Circuit Malfunction (HO2S-11) During testing the HO2S Heaters are checked for opens/shorts and excessive current draw.
The test fails when current draw exceeds a calibrated limit and/or an open or short is detected. Short to VPWR in harness or HO2S. Water in harness connector. Open VPWR circuit. Open GND circuit. Low battery voltage. Corrosion or poor mating terminals and wiring Damaged HO2S heater. Damaged PCM.

One example of this would be when an automatic vehicle in placed in gear. To prevent the added drag from the torque converter and transmission from reducing the idling speed, the PCM will command the idle control valve to allow more air to enter the engine, while at the same time, adjusting the injector pulse width to inject more fuel to suit the increased amount of air. Note that the idle air control valve is closed by the PCM when the throttle plate is opened to prevent excess air from entering the engine.

B3021 Mazda Millenia Error Code Repair Process :

For engine speed input circuit range/performance check engine light is perhaps the most troubling of lights because it could mean so many different things, from you didn't screw the gas cap on tightly enough to look out for pistons flying through the hood and into the stratosphere. The easiest way to find out what this light is telling you is to hook your vehicle up to a scan tool. B3021 error code diagnostic tool looks a little like an oversized calculator and plugs into a communication port inside the car. After you instruct it to perform the scan, it speaks engine speed input circuit range/performance with your car's computers to find out exactly what's prompting the light to turn on.

Common Causes of Mazda Millenia B3021 OBD2 Code

A common cause of code B3021 is the failure of Engine Speed Input Circuit Range/Performance, but there are several other possible causes as well, such as ;

Exhaust tube
Faulty Camshaft Position Sensor
Fuel injectors may be faulty
EVAP canister or fuel tank leaks

B3021 is a kind of Body Trouble Code

Auto body problems aren't always easy to spot. Diagnosing auto body problems sometimes requires a little know-how. In this section you'll find articles dedicated to teaching you how to diagnose auto body problems.

Engine OBD 2 Codes website is a freeware resource center for engine trouble codes.

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B3021 Mazda Millenia OBD Code

B3021 Mazda Millenia Error Code Repair Process :

Common Causes of Mazda Millenia B3021 OBD2 Code

B3021 code for other Mazda cars