P1808 BMW Fault Code

Description:

The issue covered by the bulletin involves a power steering noise/whine or fluid leak from the power steering pump, gear or high pressure side power steering hose during extreme low outdoor temperature operation.

P1808 Code Symptoms :

The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. P1808 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 P1808

P1808 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 P1808 code ?

• Continuous oil flow to the VCT piston chamber
• Dirty Oil
• Improper ignition timing
• Foreign matter caught in fuel filler cap

At this point we are assuming that the fuses and relays are good. You will need to locate the PCM/TCM and the power input signal circuit using your vehicle information source.

Unplug the connector from the PCM/TCM, place the ignition switch in the ON position, and probe the appropriate circuit with the positive test lead of the DVOM.