Need Help Diagnosing Coolant Overheat / Leak / Codes

I’ve been quite lucky to have smooth riding for about 40k miles since the last “big” job (inverter coolant pump). The advice here was essential to a smooth replacement (including removing air bubbles). I’m decently handy and have access to tools/etc for the work, however, now I’m stuck with this new problem, and not sure where to begin…

Vehicle: 2007 Prius (not sure trim level)
Mileage: ~104,000

Prior (Relevant) Work:

• Inverter coolant pump failed and replaced (OEM part via RockAuto) at ~65k miles using PriusChat guidance

Codes:

• Confirmed P1121, P1123
• Pending P1121, P1116

Symptoms:

• Check engine light
• Intermittent (few seconds at a time) triangle of death (ToD)
• No heat in cabin (on full blast)
• Leaking coolant (decent puddle), driver side near front, haven’t torn down to locate
• Can see shiny red reflection (of coolant) dripping when car running on underbody trim when looking down into engine bay between inverter case and inverter coolant pump
• Low coolant in reservoir near front (black snap cap with built in tiny hose)

I’m going to guess the best courses of action include don’t drive the car and some sort of tear-down to locate the leak(s). Before I do that, has anyone else experienced this set of symptoms, or could perhaps point me to an existing thread? (I’ve looked around but haven’t located my exact issue described and diagnosed yet.) Thanks!

 

Thanks @Tombukt2 and @SFO ! After some additional diagnosis, and blind feeling/paper towel for wet spots, it turned out to be a bad coolant control flow valve. Thankfully it’s the same repair I’ve performed previously, but certainly annoying for it to fail after only 50k miles. Went with a genuine Toyota part this round (rather than Rock Auto OEM equivalent), and I should be covered until we hopefully trade up for a 2023 Highlander Hybrid for our growing family.