U3428 BMW Fault Code

Description:

Output Shaft Speed sensor circuit intermittent failure The output shaft speed sensor signal to the PCM is irregular or interrupted.
Harness connector not properly seated Harness intermittently shorted, or open Harness connector damaged OSS sensor damaged, or not installed properly Verify harness and connector integrity Verify OSS sensor proper installation.

U3428 Code Symptoms :

If your U3428 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 U3428 and engine control unit are in charge of monitoring a bunch of different , and if they get a reading that's a little out of whack, up pops the check engine light.

Diagnosis And Repairing U3428

U3428 OBD2 reports a sensor fault, replacement of the sensor is unlikely to resolve the underlying problem. The fault is most likely to be caused by the systems that the sensor is monitoring, but might even be caused by the wiring to the sensor itself.

How to fix U3428 code ?

• EVAP system hose leaking
• Faulty front heated oxygen sensor
• Faulty ignition coil (s)
• Intake Valve Timing Control Solenoid Valve harness is open or shorted

As long as the throttle plate remains closed, the idling speed and quality is controlled by the PCM via the idle control valve, and as can be seen from the above it should be clear that idle control on a gasoline engine is a complex affair.

For instance, if the engine is started in sub-zero temperatures, the PCM will command the idling control valve to allow less air to enter the engine to enrich the air/fuel mixture to create a condition which is roughly analogous to how chokes worked on carburetted engines to control idling in cold weather.