U3594 BMW Fault Code

Description:

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 BMW 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.

U3594 Code Symptoms :

When you turn on the ignition, the Service Engine Soon or Check Engine U3594 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 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 U3594!

Diagnosis And Repairing U3594

U3594 OBD 2 code on vehicles with electronically controlled automatic transmissions, the 3-4 shift solenoid is responsible for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission.

How to fix U3594 code ?

• Camshaft Position Sensor harness is open or shorted
• Faulty Camshaft Position Sensor
• Exhaust gas leaks
• Faulty Crankshaft Position Sensor (POS)

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code U3594, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code U3594 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.