B278A Subaru H6 OBD Code

OBD/2 B278A error code description and symptoms.

Mass Air Flow (MAF) Sensor Intermittent The MAF sensor circuit is monitored by the PCM for sudden voltage (or air flow) input change through the comprehensive component monitor (CCM). If during the last 40 warm-up cycles in key ON engine running the PCM detects a voltage (or air flow) change beyond the minimum or maximum calibrated limit, a continuous memory diagnostic trouble code (DTC) is stored.

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code B278A, so consult the manual to locate the brake fluid reservoir. Bear in mind that a low fluid level can set code B278A on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.

B278A Subaru H6 Error Code Repair Process :

If your vehicle failed a B278A test and the B278A Check Engine Light is NOT on, chances are you have a problem with the OBDII system, a burned out MIL lamp, or a faulty catalytic converter. The converter is essentially an afterburner that cleans up the exhaust after it exits the engine. The OBDII system uses engine overboost condition a ownstream oxygen sensor to monitor the efficiency of the converter, and it should detect a drop in converter efficiency if the converter has been contaminated or is failing (ignition misfiring, leaky exhaust valves, and oil burning can all damage the converter). What you want to look engine overboost condition: Any conditions that might cause ignition misfire, an overly rich or lean fuel condition, or loss of compression. Use your OBD Express DIY to look at the oxygen sensor outputs, coolant temperature, airflow, calculated engine load, and inlet air temperature.

Common Causes of Subaru H6 B278A OBD2 Code

A common cause of code B278A is the failure of Engine Overboost Condition, but there are several other possible causes as well, such as ;

Damaged camshaft position (CMP) sensor
Faulty TCM or TCM programming
Faulty Crankshaft Position Sensor (POS)
Oil flow restriction in the oil passages or the variable camshaft timing (VCT) valve body

B278A 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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B278A Subaru H6 OBD Code

B278A Subaru H6 Error Code Repair Process :

Common Causes of Subaru H6 B278A OBD2 Code

B278A code for other Subaru cars