07 Suburban 5.3 wont start when temps get under freezing.
07 Suburban 5.3 wont start when temps get under freezing. Once temps get
up above freezing it fires right up. Everything works such as lights, dash, door
locks, etc. Just wont turn over.
So then we can assume that it does crank over just won't catch and run. So the first thing to test would be the sensors, if they are sending a false signal to the ECM it may think it is warmer than it really is so it won't enriched the fuel mixture to start the engine, you may what to consider having a live data scan performed, it might be the quickest way to find the fault.
Have your battery & alternator load tested preferably when its cold. And check or replace battery terminal & terminal wires and the engine grounds from battery & engine block to frame for good clean connections without corrosion. Have starter tested and/or replaced.
Also clean all electrical connections with contact cleaner (CRC) and use dielectric grease in connectors to remove moisture & keep it out.
Looking for a Used Suburban in your area?
CarGurus has 385 nationwide Suburban listings starting at $1,995.
Search Chevrolet Suburban Questions
Chevrolet Suburban Experts