Chryslermodels equipped with a total integrated power module or TIPM may exhibit a fuel pump relay control circuit failure. When the key is removed from the SaveBig on Auto Repairs. The PCM power diode is put into the fuel pump and PCM relay power circuit to prevent power surge feedback into the circuit called flyback voltage then can be higher than normal operating voltage. The computer may get flyback voltage surge and may damage power circuits inside the PCM is the diode was not used or is Frontwiper HI/LO relay: 301 — Fuel pump relay: 302 — Trailer tow battery charge relay: 303 — Heated backlight relay (SuperCrew only) 304 — PCM relay: 305 — Fuel pump HI/LO relay (supercharged engine only) 306 — Inertia switch relay (supercharged engine only) 401 — Not used: 501 — PCM diode: 502 — A/C compressor diode: 503 Fusebox diagram (location and assignment of electrical fuses and relays) for Cadillac SRX (, 2012, 2013, 2014, 2015, 2016). Thevehicle being tested is a 1999 Chevy Suburban with no fuel pressure. This truck had a new fuel pump installed and still did not have fuel pressure. In th Fusebox diagram (location and assignment of electrical fuses and relays) for Pontiac Grand Prix (, 2006, 2007, 2008). .

when a fuel pump relay is bad