This could be a problem with the shielding on the highlighted wire that is on the charging circuit wiring diagram that I have included for you in the diagrams down below. I have also included a guide on how to find a short to ground and how to induce intermittent conditions in an automotive electrical circuit for you as well. You will need to use a Digital Multi-meter to use these guides, so here is a link below explaining how to use one, if needed:
If the shielding around the wire is okay then there is also a possibility of an intermittent short to ground in the highlighted wire in between ECM/PCM and the gauge control module causing the warning light to illuminate. Please go through these guides and get back to us with what you are able to find out.
Images (Click to enlarge)
Sunday, December 1st, 2019 AT 8:23 PM