Code 43- Power supply to the fuel injectors and fuel pump is not normal......Probable cause of malfunction......open or short circuit in wiring harness, or malfunction in ECU. Page 7-10 in manual. Diagnostics are on page 7-22.
Take the fuel pump relay out......warm it up so the grease inside softens, re-install it and your sled will start. This doesn't fix the problem, but when its -30 and you're 10 miles from home like we were, it'll get you home.
I got this code today on my Nytro....I changed the relays but still nothing so I ran a wire from the positive on the battery to the positive terminal on the fuel pump just to get me out. Hopefully will get a chance to diagnose the problem this week. I am sure it is something simple!!
It is not grease that makes the relay stick. When the relay gets warm then cools off to super cold temps (10 below f or so), a layer of frost forms on the relays that are contaminated with internal moisture. That insulates the contact points in the relay and prevents current from flowing to the fuel pump and injectors. Warming the relay up by putting your hand on it or turning the key on and off several times should break through the frost and make contact! Get a new relay when you can!!!