2013 Tundra no battery light. charging system faulty

Did you clear the code, drive the truck and see if it comes back?

It’s a code for rough idle.

Could have been a “glitch” from running the truck on low voltage with no charging.

If it comes back cleaning the throttle body would be a good start

 

All right Jeff. You a good help walking me thru tundra diagnos process … I learned a lot . The abs and skid light never came back on. I just deleted the P1605 code. We shall see what it spits out later. Thanks again. We use the truck last night to gathering . Came back good no trouble. Now I just delete the one code. We shall see what it tell us later, if it comes back. I bet not. I’m underdog fixer now. Graduate from tundra university .

 

I've been getting similar issues to the OP. I've tested the 4 pin connecter ignition off, on, and with engine running. My black wire (pin 4) has 0v the entire time. I cannot figure out where this traces back to. I tried to look on that link with the diagrams and apparently I'm not using it correctly because I cannot find any diagrams for the charging system. I have a 2017 5.7 tundra

 

Pin4 black is the control for the battery light on the instrument cluster. If yours is 0v that would be your light is on, on the dash.

Is the truck charging when running? What is the voltage across the battery terminals as it’s running.

 

Break in the black/yellow wire was my issue. thank you very much for all the useful info in this thread Jeff_5_7 you helped me solve my issue.

 

All good and charging now? First time I have seen the Black/Yellow wire fail like that.

 

Can I piggyback onto this thread too. Similar issue. Just put in a new alternator. No output. B/Y and G/Y both show 12+ with key on. R and B show 0V. Is the Red wire an output to the ECM? I'm thinking I just got a bad alternator but want to make sure before doing that PITA job again.