U0556 Trouble Code

View U0556 obd/2 error code description and symptoms. U0556 engine photo

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. 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) U0556 DTC is a check of the VCT unit.

A good starting point in your diagnosis is checking all system fuses and fusible links. This can be done using the DVOM on the voltage setting. You will want to test the fuses with circuits loaded. Some fuses will appear normal until a load is placed on their respective circuit; at which point they will fail. This has been the cause of many 'phantom malfunctions'. Consult your vehicle information source for fuse and fusible link locations. If all fuses are in working order, you may want to check TCM relay operation by swapping identical relays. Usually the horn relay, starter relay, fuel pump relay, air conditioning clutch relay, and controller relays are similar enough in design to swap for diagnostic purposes.

U0556 Error Code Repair Process :

If your torque converter/brake switch b circuit low check engine light is illuminated, it's best to take it in for diagnostic testing, which can feel like a hassle. Because while the lights vary in appearance from vehicle to vehicle, all have the same basic meaning: There's a problem with the car's emissions system. The on-board diagnostics system U0556 and engine control unit are in charge of monitoring a bunch of different torque converter/brake switch b circuit low, and if they get a reading that's a little out of whack, up pops the check engine light.

U0556 is a kind of Network Trouble Code

U-code indicates that engine communication errors and shows lost communication with engine parts.U-Codes are fairly straight forward, given all of the articles and technical publications that have been written regarding these problematic codes. In most cases, it just comes down to identifying the module that isn't communicating with the other modules on the CAN bus line for whatever reason.

Common Causes of U0556

A common cause of code U0556 is the failure of Torque Converter/Brake Switch B Circuit Low, but there are several other possible causes as well, such as ;

Camshaft advance mechanism binding (VCT unit)
EVAP system hose leaking
Intake Valve Timing Control Solenoid Valve harness is open or shorted
Failures of clutch motion/travel sensors.

U0556 code for all cars

You can view according U0556 DTC for your car model. We selected several models to see obd2 solutions click and view it.

+U0556 Mercedes Clk 240

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