Code Definition

P15F8 — Integrated Supply Module (ISM) Power Supply Fault

System: Powertrain  |  Type: Manufacturer-Specific  |  Make: BMW

About P15F8

P15F8 is a manufacturer-specific powertrain diagnostic trouble code recorded for BMW vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

P15F8 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

The Digital Motor Electronics (DME) monitors the Integrated Supply Module (ISM), which switches and distributes battery voltage to multiple engine management circuits and loads such as engine sensors, ignition coils, and fuel system actuators. DTC P15F8 is set when the DME detects an implausible voltage output, incorrect switching state, or loss of feedback from the ISM, indicating that the module is not supplying or regulating power as commanded. The ISM is typically commanded by the DME via a control input and reports back through a feedback line, so faults can originate from either the ISM ...

Join TaT to view the complete code information and diagnostic details.

Quick Facts