Hey everybody, my wife's 2013 Rx350 has been pretty amazing for the most part. We bought it a couple of years ago with about 75k on it and are now at about 95k.

It has been parked for a couple of weeks while she has been away visiting her parents and I have been working out of town. Today I started it up and the check engine light came on, and the dash said "check AWD system". I drove on to O'Reilly to get a diagnosis but they don't do that anymore thanks to the virus. I had less than a quarter tank of gas, so I refilled the tank and made sure the gas cap was securely tightened. No help. Back at home I tracked down my Bluetooth OBDII adapter and plugged it in. It kicked up five codes!

P0031 - heater control circuit low
P0355 - ignition coil misfire
P0368 - camshaft position "B" circuit high
P2238 - O2 sensor positive current control circuit low
P2253 - O2 sensor positive current control circuit high

This seems like a ton of codes. And it is rather bizarre that they would all come up at once. The car felt a little off to me while driving, but I am no mechanic and that could just be the power of suggestion.

I will say, the links to a website give locations on three of them as "bank 1 sensor one", another is just "bank 1", and another gives no location. So perhaps sensor one is bad?

Normally I would just go to a mechanic, but it's Saturday evening. Complicating things is the fact that I am due to drive 600 miles round trip to pick up my wife and two year old son tomorrow. My vehicle is unsuitable for the trip. There is a possibility of postponing for a week, but I have already been away from them for three.

Any thoughts on the matter? I would just like to have an idea of what I'm dealing with.

Thanks! David

 

One thought is, during the idle time, varmits like mice, could have made a home nestled among wiring and chewed a bit. It has happened to me, even parked in a garage.

 

Weak batteries often throw spurious warning lights and codes. That would be my first suspicion given the length of time the vehicle sat unused.

 

+1 on battery...charge it overnight but load test it first to see the condition.

 

Thanks for the responses! Unfortunately I don't have a charger of any type. This . Any thoughts?

I had told myself that if the battery was original I would just replace it without testing, since it would be seven plus years old at this point, but the one in there is an econocraft, which I am pretty sure is not original. It has no date on it.

I am willing to try messing with the battery to avoid having to go to a mechanic. Would you guys recommend buying a charger or just going ahead and swapping the battery. Or is there a third way?

Thanks again! David

 

​​​​​​

Well, I bought a charger at O'Reilly last night. It wasn't the cheapest or most expensive, but did have good reviews. It is hooked up right now. I'll update after the battery charges and I test drive. Hopefully this will solve the issue.

 

Well, charged the battery fully and tried to clear the codes. The check engine light went off for like three seconds before coming back on. Just two seem to remain though - P0355 and P0368. Maybe it's time to go to a mechanic? Any thoughts?

 

This might sound crazy but is your engine oil level ok? I think one of the codes is the camshaft sensor or something. I was on a road trip when I got a similar code on my Prius. The guy at AutoZone in Utah checked my oil level and told me to add a quart. I drive for about 2 miles and never saw the code again. Maybe yours is different but check it.

 

Thanks Nick, I never would have thought of that! I read your advice and checked it before going to the mechanic. It was at proper level, which was good, since I think I got it changed only a month ago.

So driving to the mechanic I could tell that something was definitely off. It stuttered a bit while accelerating. The mechanic hooked up his computer and said I need to replace all the plugs and coils. Seemed a bit extreme to me, but I do trust the guy. He said that there was a known defect, but Lexus has refused to recall.

Does this sound reasonable? It sucks to be replacing all of this at only 95k miles, but if it needs to be done then I want to do it.

 

It sounds reasonable if your plugs were never changed. Same for coils. Do you know if the plugs were ever replaced? Also I'd go with the original replacements for plugs.

 

I doubt plugs were replaced. We got it with about 75k miles on it.

 

I'd suggest you go on the Lexus Owners site and get a picture of your car's history of maintenance. It should show you all services performed.

 

Good call, forgot about that site. Turns out that the vehicle was still saved in my account from when I looked at buying it! There were a few records from some major service events, but they were apparently getting their oil changed elsewhere and I didn't see anything about plugs. They did have the Lexus dealer get gum off the seat lol.

The mechanic said he can get to it on Monday, so I'll probably end up doing that.

 

The Owners manual calls for the spark plugs to be changed at around 100,000 miles. It is almost a certainty they have never been replaced. Doing the coils at the same time is a good idea, especially the rear bank that is hard to access. I have seen too many people replace one coil that is known to be bad and then another one goes bad soon afterward. May as well do all of them now.
The car should drive like a dream after this work.

 

This is a very encouraging reply, thank you! I am definitely not opposed to spending the money if necessary, I guess I was just getting my hopes up with thoughts of a battery recharge or gas cap tightening...lol. So it is nice to have some affirmation that this is the right decision. I'll call him in the morning and let him know that I'm all set for Monday. Thanks Clutchless and everybody else that replied!