To set the stage, it is not my car, nor did I experience it. I received a call from a friend who has a 2000 SSEi, totally stock, about 95k miles. Been on the freeway about 5 minutes, total drive time about 10, when she heard a warning ding. Only thing displayed was "low tire pressure" which went off the day before and came on when she started the car. Then, she said the dings just started going off like crazy, and that was followed by what she described as a sound like a warbling siren (like when they approach on intersection). She pulled to the side, saying it felt like it lacked power, then got off at the next exit.

I checked for codes - none. Tire pressure on right rear was down about 5 pounds. Filled that up with the accessory kit, and drove it to her place without incident. She insists it was from inside the cabin, and was not from the ventilation system. I pulled the cabin air filter and checked anyway. No problem found there.

Temps normal; tranny fluid normal; oil ok; belts, tensioner ok; both front hub replaced less than a year ago; battery voltage normal; all cables and grounds previously cleaned. ac working ok; power steering fluid good. The CEL did not come on, no codes, and nothing on the DIC except for the low tire pressure.

Anyone ever have a similar experience? I know some have had dash issues. Anything like this? I haven't found a cause, and the problem did not reoccur during the 15 minute drive afterward.