I did some digging before posting another about the triangle. This is for a CO workers car. We did some digging here and other places and can't find too much info on our particular issue. He's got a 08 with 130k. It runs fine. Battery charges and discharges just fine but Red triangle, abs and check engine has come and gone for awhile now it stays on all the time. Hev battery still works fine. Clear the codes it comes right back on. It's got the p3000 codes but it seems they point to first diagnosing HEV ECU faults. We have a P0560 in the HEV which from another post here seems to be related to the Engine ECU 12v signal. Wouldn't the engine not even run without the ECU 12v signal? I'm trying to figure out if we have multiple issues or are the 3000s because of this HEV DTC that points at possible engine ECU failure. Multiple 3000 code issues I've seen the battery doesn't function properly anymore. Ours does. We have yet to check engine module E7 pin 6 to verify. If it comes down to engine ECU can we get used? Just needs immobilizer programming correct?
My first recommendation would be to ensure the code reader you're using is actually prius friendly. Too many people end up chasing their tails due to the code reader not correctly displaying the real codes. The second recommendation is to verify the 12v battery prior to any significant troubleshooting, as that can also lead to chasing ones tail. The Toyota batteries have a date code stamped on top. It's usually covered by the mounting clamp. If it's the original, it may be worth replacing.
I had an embarrassing red triangle of death appearing on tight left hand corners, then started on every corner and when braking hard ..... turned out the oil level was low ... how embarrassing, no more red light now the sump is full again T1 Terry
Check all the connections inside the battery case especially the battery ECU; take apart and inspect pins for corrosion or burning out. Inspect all points on the long wiring harness for corrosion (usually has a lot on the bus bars) and/or broken wires (very thin/fragile). GOOD LUCK!
