U3522 BMW Fault Code

Description:

Variable Cam Timing Over-advanced (Bank 1) The comprehensive component monitor (CCM) monitors the VCT position for an over-advanced camshaft timing.
The test fails when the camshaft timing exceeds a maximum calibrated value or remains in an advanced position.

BMW cam timing improperly set No oil flow to the VCT piston chamber Low oil pressure VCT solenoid valve stuck closed Camshaft advance mechanism binding (VCT unit) U3522 DTC is a check of the VCT unit.

U3522 Code Symptoms :

The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. U3522 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 U3522

U3522 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 U3522 code ?

• Erratic camshaft position due to low oil pressure
• Faulty Variable Camshaft Timing (VCT) position solenoid
• Faulty oil control valve (OCV)
• Improper ignition timing

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code U3522, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code U3522 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.