tuanle785

I have a 2000 rx with 97K a I have engine code 1150,1320,1349,1656 and once I reset the error codes all goes away but 1656 but eventfully they call come back on after driving. My problem is it shifts jerky from gear to gear. but once in gear it accelerates as it should. the fluid is new and what I been doing is as its about to shift I just take foot off gas and let it shift and its not jerky. but I have to get this problem fixed took to a transmission shop they suggest a new trans but I have a feeling its an electrical issue. Please help anyone. thanks Ive owned many lexus cars and never ever encounter anything like this.

Lexmex

1656 is an OCV circuit malfunction (bank 1)

OCV is Oil Control Valve

For Bank 1, note the location below on the driver's side.

There is a bolt that hold the valve down and an electrical connector (seen in the second photo).

In the third photo is a separate large bolt on the side and this hold the filter and o-ring for that OCV valve.

A great number of issues with this code relate to a dirty valve.

A mechanic might be able to check the OCV valve if it is functioning normally (they run $100 or so, so that's adviseable) with the filter running about $8 and the o-ring about $3.

Lexmex

If it were an issue with Bank 2, then it would P1663 as the OBD2 code.

Bank 2 is located just a bit further back.

In the third picture you will see the smaller bolt that hold the OCV valve in place.

In the last photo, the OCV valve is circled in yellow and the larger bolt that holds the filter and o-ring is circled in white.

Lexmex

Disconnecting the battery to help the vehicle re-learn may help.

Additionally, here the oil in question is not transmission fluid, but rather engine oil, so make sure you keep up with regular oil changes and use a good oil, preferably a synthetic.

sktn77a

iTrader: (2)

No **** Sherlock! At least you had the good sense to hi-tail it away from those clowns. But how many people actually fall for this crap?

I must confess, I gave up DIY auto wrenching 20 years ago but I know enough to know when to take it to Lexus for a second opinion. After all, who sees more of these cars than everyone else combined? I know, dealers can be crooks and incompetents too but I'd take my chances with the dealer over an unknown place.

I really struggle with where to take my cars these days - not many good independents that I know of in my area but the dealers charge an arm and a leg. So I try to take the complex things (like this posters problems) to the dealer - they have the equipment, parts and experience to fix most things, and the routine stuff to the locals - hopefully the won't screw up an oil change!

tuanle785

lexmex thanks alot for the info I will try this tomorrow, but is this the reason for the jerky shifting between gears? and sktn77a I did take it to 4 different shops and even the dealer and they all said replace transmission but being a car guy, my gut tells me its something simple like a solenoid or what lexmex was describing . I will update tomorrow when I get done checking the ohv valve or should I buy a new one first and just go ahead and replace it?

tuanle785

on another note, I just bought this yesterday off cragislist and he advised me of the rough shifting but it still drives fine just between gears is the issue so I took a gamble of it being something simple like a solenoid. what I did not know till I got home and started to trouble shoot was the check engine bulb was missing from the cluster. I got played but in his defense they got it off ebay just 2 months ago and this shifting problem just started for them so in a sense they got scammed these were an elderly couple I dont think they would of pull this, anyhow I was kinda scared at first then after I read that most them codes were electric issues I felt better about it cause they gave me a killer deal on it and its in great shape. thanks for all the help so far. ClubLexus is the Best! any more advice would be great. thanks again.

Lexmex

I'd have it checked out first (they're not cheap from the prices I checked).

I actually think it probably is related to something there in the OCV (and not elsewhere) and/or perhaps in the oil, such as a foreign object. P1349 (vvt system malfunction bank 1) is one of those codes that would also come up, so there could be an issue there. Any foreign object should normally clear the OCV filter and go back into the rest of the oil and be caught by the oil filter. Keep in miind that can affect engine timing and there is a sync between the engine and the transmission via the torque converter/flywheel.

If you have an AWD RX, I have found that changing out old gear fluid has a positive effect on gear changes, particularly 2nd to 3rd, but in this case the CEL is there for a reason.

tuanle785

that makes great sense I'm gonna go ahead and wait till monday and order the valve and o rings and filter b4 I start might as well instead of taking it apart just to see. thanks againg lexmex

tuanle785

ok so I just went out to and since the ocv and filter was easy to take out ant check I did the filter looks great I even took out and blew out with air and a it looks great condition. also I couldnt check the valve so I unpluged the battery and same code again 1656 so Im gonna buy a new valve monday morning. and i'm sure the other codes get set because of this also, I'm still a little scared about the trans issue but shifting from the gears while park is smooth and as long as im not accelerating it will still go into gear smoothly and once engaged it goes as should my only issue is in between gears which to my understanding is a solenoid that controls that. well hopefully a new ocv valve will at least clear up the check engine light. thats a start right. thanks again oh and is the O-ring u talked about earlier on the valve towards the top correct?

Lexmex

My correction, you are correct, there is an o-ring for both the valve and also one for the filter.

sktn77a

iTrader: (2)

Well, that's kinda sad that Lexus couldn't interpret the codes. Makes you wonder what happened to the "World Class Customer Service" they built their reputation on when they first introduced the brand here. I guess they truly are Toyota now!

And man, you must have been haulin' *** yesterday, buying a car and taking it to all those places for an opinion - good luck!

tuanle785

yeah man i am efficient. lol ok lexman took it apart as stated earlier this morning and cleaned the filter and valve out and behold it shifts a little smoother not jerky like before between gears but u can feel it kinda rough but not violent by no means. I still get code 1656 but other codes are gone for now. so I am positive them other codes are related to the 1656 anyhow since thats the only code and its not an open or close circuit code do u think I just need to replace the valve? or is it another issue causing that circuit to trip a code like a Ecu issue? tomorrow im gonna have access to all data and see what the normal ohms should be and see what range I should be at but shifting is better after i cleaned out the filter this morning. so I got my fingers crossed! if worst case is the valve then its a blessing! I have hope casue it does not jerk anymore just a hesitant shifting but not bad. shifts like a 4cly camry if you know what i mean

tuanle785

yeah an as for them shops that simply said replace transmission they were just being lazy as in diagnosing it. I be pissed if i actually spent the thousands replacing it if it is just a 100 dollar valve! happened to me on my accord. I had a shfiting issue they diaganoise and said I needed a whole engine wiring harness. after many hours and money replacing it all it was, was a transmission solenoid. beww. so that why I am more aware b4 listening to tech guys, I do as much research as possible b4 listening to the so called professionals with a name tag!

Lexmex

One thing, and I think this may be possible, is that you could switch out the supposed bad valve on bank 1 and take the one from bank 2 and stick it in bank 1 and see if the P1663 code comes up related to bank 2. We do a similar trick when we get engine misfires and switch a bad coil with one of the other 5 good coils and then confirm via OBD2 scan that a coil is bad.