P0170 - FUEL TRIM MALFUNCTION (BANK 1)

Basically, the DTC code P0170 OBD2 indicates that the PCM (for its acronym in English Powertrain Control Module) has detected that the fuel setting is not within the specifications that the manufacturer has set. The fault can originate because the fuel adjustment is positive or negative. Otherwise it tells us that there was a malfunction in the control that the PCM has in the air / fuel ratio.

The PCM (Power Train Control Module) receives information from the O2 sensors (Oxygen Sensor) that are used to adjust the amount of fuel the engine receives. This action that the PCM does, is known as fuel compensation.

In case the signal sent by the O2 (oxygen sensor) indicates that less fuel is needed, the PCM takes it as a negative fuel adjustment. And if the Oxygen Sensors indicate that more fuel needs to be added, this represents a positive fuel adjustment.

• Check Engine light on the board.
• There is a loss of power.
• The operation of the motor is unstable.
• Low fuel consumption.

The factors that can lead to the establishment of fault code P0170 are the following:

• Vacuum leaks.
• There may be oil present in the fuel.
• Depending on the model of the vehicle, the turbo charge air hoses may leak.
• The MAF Sensor (Mass Air Flow Sensor) or Oxygen Sensors connector may be contaminated by oil.
• MAF (Mass Air Flow) sensor defective.
• One of the O2 (Oxygen Sensor) may be defective.

Before the diagnostic code P0170 OBD II you can do the following to solve it:

• Perform an inspection of the Mass Air Flow Sensor (MAF). Make sure the electrical connections are in good condition. Repair if you find problems in one of these. Change the sensor if necessary.
• If, when disconnecting the sensor, you do not see oil in the connector, check the fuel pressure for leaks in the regulator.
• If you have access to a scanning tool, look at the MAF Sensor (Mass Air Flow) reading. Compare with the manufacturer's specifications and in case of not being within those specifications proceed to replace the MAF sensor.
• Check all vacuum hoses and make sure there are no cracks in them.
• Check the connectors of the Oxygen Sensors (O2). Check them for oil. Repair the cause of the oil leaks and change the O2 contaminated by oil.