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U0443 BMW Fault Code

Check U0443 OBD Fault Code Reason
Description:

BMW HO2S Sensor Circuit Malfunction (HO2S-11) During testing the HO2S Heaters are checked for opens/shorts and excessive current draw.
The BMW test fails when current draw exceeds a calibrated limit and/or an open or short is detected. Short to VPWR in harness or HO2S. Water in harness connector. Open VPWR circuit. Open GND circuit. Low battery voltage. Corrosion or poor mating terminals and wiring Damaged HO2S heater. Damaged PCM.

U0443 Code Symptoms :

See U0443 in engine

The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. U0443 code had an elaborate diagnostics procedure, including showing engine trouble codes on the air conditionning display. However, the system was troublesome, misunderstood by customers, and a rash of unpredictable failures led to the technology being quickly retired.

Diagnosis And Repairing U0443

U0443 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 U0443 code ?

See U0443 repair manual
  • Damaged camshaft position (CMP) sensor
  • Faulty Mass Air Flow (MAF) sensor
  • Air fuel ratio (A/F) Sensor 1 Bank 1 harness is open or shorted
  • Faulty Intake Valve Timing Control Solenoid Valve

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code U0443, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code U0443 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.

BMW Cars that meet U0443 error