The utility model discloses multi -purpose vehicle(MPV) failure diagnosis is with showing lamp, the utility model relates to an instrument that car failure diagnosis used, the engine oil -gas separator comprises a housin, test stitch and lamp, the test stitch includes the test stitch that many test cap shapes are different, the bottom of casing be equipped with respectively with many the corresponding test through -holes in test stitch bottom position, multi -purpose vehicle(MPV) failure diagnosis is with showing lamp still includes mode switch and diode subassembly, the diode subassembly is parallelly connected with the lamp, mode switch establishes ties in the one end of diode subassembly with the parallel circuit that the lamp forms, the top of many test stitchs is connected with the parallel circuit's that the lamp forms the other end with the diode subassembly through the wire respectively, the diode subassembly includes the emitting diode and the resistance of series connection two parallel circuit one end that emitting diode forms of two reverse parallel connections. The utility model discloses can enough measure pulse signal again can the measuring current signal, the test stitch that has multiple different specifications, and be convenient for and various connectors firmly are connected, to the not damage of jack of connector.