C3938 Porsche 914 OBD Code

OBD/2 C3938 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.

Circuit High Input codes like C3938 are mostly caused by defective alternators that develop excessive voltages, although there may be other causes as well, such as short circuits that 'leak' current into a particular system from other, unrelated systems that work on higher voltages. Note that in the case of short circuits that leak power into a control circuit, there is likely to be other, seemingly unrelated trouble codes present along with the code(s) being investigated. Diagnosing a 'high input' code will always involve a thorough testing of the charging system as a first step, followed by measures to isolate the system from all other possible sources of power during resistance, continuity, and reference voltage tests.

C3938 Porsche 914 Error Code Repair Process :

When you turn on the ignition, the Service Engine Soon or Check Engine C3938 light should flash briefly, indicating that the OBD system is ready to scan your vehicle for any malfunctions. After this brief flash, the light should stay off while you drive as long as no problems are detected. If dc-dc converter failure so, you'll be glad to know that your vehicle is equipped with an early warning system that could save you time, money, and fuel in addition to helping protect the dc-dc converter failure.

Common Causes of Porsche 914 C3938 OBD2 Code

A common cause of code C3938 is the failure of DC-DC Converter Failure, but there are several other possible causes as well, such as ;

EVAP canister or fuel tank leaks
Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
Incorrect fuel pressure
Faulty Intake Valve Timing Control Solenoid Valve

C3938 is a kind of Chassis Trouble Code

Diagnosing chassis noises can be one of the most frustrating problems technicians face. Fortunately, manufacturers have engineered noise, vibration and harshness (NVH) diagnostic techniques and equipment to find the source of the noise.

C3938 Porsche 914 OBD Code

C3938 Porsche 914 Error Code Repair Process :

Common Causes of Porsche 914 C3938 OBD2 Code

C3938 code for other Porsche cars