A Fawkes 1.6AT car with a mileage of about 13 thousand km. The engine will intermittently flameout, but it can restart the engine. Fault diagnosis: due to the normal operation of the engine when receiving the vehicle, it is decided to conduct routine inspection first. Test spark plug combustion, no "flooded" phenomenon; jump fire test, spark in blue and continuous; use fuel pressure gauge to measure the fuel pressure, to 350 kPa. At this point, no abnormalities were found. With IDS check, 2 historical fault codes (CMDTC) are read, which are "low voltage of P0689----ECM/PCM power relay perception circuit" and "low voltage of P0562---- system". According to the fault code prompt, it is suspected that the PCM power relay (R14) is not working well. First check fuse F23 and fuse F12, connect normal; check PCM power relay, appearance is no exception, and connection is normal. Start the engine, gently tap the PCM power relay, the engine suddenly flameout, disassemble the PCM power relay, and find its internal contacts open. Elimination method: replace the PCM power relay.