DF018 Volkswagen T4 OBD Code

OBD/2 DF018 error code description and symptoms.

Low Speed Fuel Pump Primary Circuit Malfunction The PCM monitors the low speed fuel pump (LFP) primary circuit output from the PCM.
The test fails if: When the LFP circuit is commanded on (grounded), excessive current draw is detected on the LFP circuit; or when the LFP circuit is commanded off, voltage is not detected on the LFP circuit (the PCM expects to detect VPWR voltage coming through the low speed fuel pump relay coil to the LFP circuit). Open or shorted low fuel pump (LFP) circuit Open VPWR to low speed fuel pump relay Damaged low speed fuel pump relay Damaged PCM An open circuit or short to ground can only be detected with the low speed fuel pump.

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.

DF018 Volkswagen T4 Error Code Repair Process :

The rule of DF018 code when it comes to emissions-related vehicle repair is that any modification that changes the vehicle from a certified configuration to a non-certified configuration is considered tampering: this applies to both vehicle owners and repair facilities and is, therefore, a Federal offense. Replacing a catalyst with a straight pipe is one traditional example of air suspension lf height sensor circuit failure. Likewise, overriding the OBD DF018 error in system through the use of high-tech defeat devices or non-certified computer chips, for example, would also be considered tampering. The OBD system may, however, be repaired back to its original certified configuration with certified performance chips or appropriate aftermarket parts.

Common Causes of Volkswagen T4 DF018 OBD2 Code

A common cause of code DF018 is the failure of Air Suspension LF Height Sensor Circuit Failure, but there are several other possible causes as well, such as ;

EVAP canister or fuel tank leaks
Failures of clutch motion/travel sensors.
Erratic camshaft position due to low oil pressure
Engine Control Module (ECM)

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DF018 Volkswagen T4 OBD Code

DF018 Volkswagen T4 Error Code Repair Process :

Common Causes of Volkswagen T4 DF018 OBD2 Code

DF018 code for other Volkswagen cars