P0328 Engine Code
 

So, last night (Wednesday) I got a P0328 engine code. The code comes up as a Bank 1 knock sensor high, with voltage exceeding 4.83V for 1 second or more. The car is in "safe mode" until my appointment Monday morning.

Causes? Could be a bad sensor. Could be the ECU. Other cars say bad gas. And yes, I filled-up Wednesday morning with gas. I'm going to check the pump to ensure it was Premium (it's a pump at work).

I plan to burn through as much of the gas as possible, and re-fill with gas from a different station/pump. Car had 2780 miles when the code popped. The car also won't crank immediately. You turn the key to "crank", nothing. After 2-3 times, it will crank just fine. Car runs, low on power, and the injectors are noticeably quieter.

Any thoughts from anyone?

could be a bad knock sensor :/

That's my thought. Subarus seem to have this problem later in life (80K+). I'm hoping it's simply a bad sensor. Or just bad gas.

I agree, check the sensor, or the harness leading to the sensor. To read close to 5v dude you had to have head serious detonation, did you here the Ping? or was it phantom? (meaning you didn't hear anything)

The engine starts up very quiet. It's so quiet, it sounds like the high pressure injectors aren't even running. So no, I don't hear the pinging.

I'm concerned that if it is the sensor, how long it will take for Scion/Toyota to order me one....

Sorry I wasn't clear, I meant when the knock event happened (check engine light indicated).

Well, I've reset the code, and restarted the engine, and I can't hear the event. Event while running and clearing the code, I don't hear it. Did I hear the event when the code first popped in? Nope.

A five volt knock, you would have heard unless you had the windows down, or listening to the radio too loud. What were the driving conditions when it happened? Also is the car STILL in safe mode? Right now it appears to be a faulty knock sensor.

G

There were no driving conditions. I drove home, parked it, went inside. Came back out later, started the car, the check engine light popped on. And yes, the car is still in safe mode. Even the cruise control won't work.

By driving conditions I meant, asphalt? concrete? dirt? gravel? were you just cruising? hammering? Obviously the Knock occured prior to you parking it, unless it is a harness short, then maybe the harness shorted when you started it.

***DO AT YOUR OWN RISK***

I hammered on my FR-s during a crest run (I mean hammered) It was an attempt to climb to the peak at the fastest possible time, and yes I can drive so I beat the tar out of the car. When I reached the top, brakes red, tires melting, but idling fine, temp good, no issues. Let it idle for a few minutes, then shut it off to let everything cool down. Got in to drive down (like a grandpa) and first turn boom! check engine light and safe mode. Get home pulled code, now mine was different than yours however, I unplugged the battery and the car went out of safe mode. You can attempt this if you want, however if it is a bad knock sensor, or a harness short then the car will go right back into safe mode. I know it sucks not having full throttle, or the ability to go over 3k, but it seems something is VERY wrong.

Have you taken it to the stealership yet? Anything thus far should be well under warranty.

G

Ah, conditions were 73mph on an interstate coming home from work. Nothing hard or fancy with the car. Just a normal daily commute. And yes, I tried disconnecting the battery for 20 minutes, and once running, the light came back on.

I went to the dealership this morning. All they could do is schedule me for an appointment on Monday at 7:12am. The guy also said it could be a faulty sensor, but he also just scheduled the cars, and doesn't work on them. I mentioned the TechStream, and he said "yeah, they will hook it into a laptop".

He did say the car should be fine as long as the check engine light doesn't start flashing. And the car will go over 3k, but is a DOG in driving. Feels like a Yaris. I'm just going to baby it and see what they tell me Monday. The sensor is electrical, and being an engineer, I know failures happen.

Please keep us updated once you get a diagnosis. Not sure how hard this would be but I wonder if you could switch each banks sensors to the other bank and see if the problem switches as well. That would almost prove a bad sensor.

Yes, I plan to post updates. The sensors are on the top of the engine, below the intake manifold. Honestly, I'll let the dealer mess with it. The wiring harness looks fine, so I'll let them take it apart.

*UPDATE*

Toyota inspected my car. They said everything seems to be fine, and the tech thinks it's bad gas. He said the knock sensor is reading right. The ECU is reading right. Fuel trims are reading right. He suggested to burn through the tank and a partial of a fresh tank and see what happens. After refilling, reset the code and see if it stays off.

If fuel doesn't fix it, he said he'll have to keep the car while he discusses with Toyota on further testing to locate the problem.

I will continue updating once I finish this tank and get a fresh tank.