thermostat, RPM, speedometer needles aren't working. TPMS, VSA, engine, brake, seatbelt and ABS lights all stay on and the A/C stopped blowing cold air. Weird enough, my gas gauge still works fine. I checked all the under-dash fuses and they all work. Anybody know what might be going on?

 

The gauges and indicators are part of the multiplex integrated control system. The ECM/PCM probably lost communication with the gauge control module.

You can try a battery cable reset (to reset the multiplex control system).

Honda has two different methods for the battery cable reset.

1. One method is to disconnect the negative cable (disconnect negative first) and then positive cable. Then connect them together with a jumper wire for 15 minutes.-- Do not touch the battery terminals. You'll need the radio's anti-theft code afterward.

The 15 minute reset doesn't require turning the ignition ON, etc.

https://honda-tech.com/attachments/h...able-reset.jpg

2. Honda has a variation of the battery cable reset which requires turning the ignition on and off; but, only requires 10 minutes. This video is the 10 minute method.

 

you know your stuff. Endless thank yous!