What's the p1727 BMW code?

A signal error from the crankshaft position sensor may be triggered by the common p-code p1727 for the BMW models, but it simply means a contact error between the engine control module (dme) and the tcm (transmission control module) that may include a signal error from the dme to the crankshaft sensor. If You have installed the CKP sensor and there is still an error on the dashboard lit up the sensor may have been installed wrong and will need to be re-installed properly. You will most likely have to perform a diagnostic before knowing what the issue is. The cost for the replacement part is listed as approximately $70 - $100 on average.