good day all!

I spent over 6 hours researching and trying to get my 2007 RX 350 to clear these odd codes!! (only 78K miles with one owner dealer service)

I have a 0304 cylinder misfire? changed all three plugs (in front bank) and coil packs with Denso OEM like products plugs iIthink were 3426? and the coils 673-1309 made in Japan, I assumed with would clear THIS code and it didn't ...trying to find a reason why ??? possible injector or vacuum leak or lost compression or kink in harness ??

each time the code triggered (check engine light came one also the VSC light was present related or coincidence IDK????

I used my scanner and was able to access the ABS system and a punch of codes appeared

U0073 control module communication off
U0123 lost communication with yaw rate sensor module
U0124 Lost communication with lateral acceleration sensor module
U0126 lost communication steering angle sensor module
C1223 Malfunction in ABS Control System
C1201 Engine Control System

I am trying to get this vehicle road worthy for my daughter to get back to college and doing other PM items to have her stealership free for a while until she comes back in Nov i am truly stumped been working on cars over 30 years Ford, Honda, Toyota, Jeep, Dodge etc...

 

How old is your battery?
Do you have rats in your area?

 

Battery 2 days old sears die hard platinum i brought the car a week ago from a neighbor who rarely drove it maybe 3k miles in last 3 yeats

 

I would do visual inspection of the engine bay wiring and remove the glovebox and look around there too at the engne ecm and make sure no wires are chewed.

Did you buy the car with check engine light on?
Be careful on our cars unplugging a scanner with the key on, it can sometimes do wired stuff with some scanners and throw communicaton codes but they always clear when removing battery terminal for a few mins.

 

Yes brought the car recently and as soon i was driving 15cmins the check engine light came on code cylinder 4 but new plug and coil didnt resolve it and each time the vsc pops up too giving me what appears to be tge abs engaging when i come to a stop
ill keep checking for damaged wires in the harness somewhere t points to something electrical

 

When you put your finger on the $4 injector(at connector) you should feel that injector thumping like the rest.
I use my index finger and can feel all my injectors on the front bank thumping about the same.

If you unplug the injector on the bad cylinder is there a change in idle?
If you unplug the coil on that cylinder is there a change in idle?

You are probably in limp mode if it's driving funny and dash is lit up like a christmas tree. lol

 

Txs i just reset the codes for the umpthteen time and driving around the code hasnt appeared yet

The number 4 cylinder injector harness wasnt pushed all the way in and after i did i coykd feel the pulse but not as pronounced as the outside 2 but it seems while driving the abd didnt engage as often as before outside from a weird loud clunk when downshifting coming to a light
not used to this time of tranny under the hood looks brand new cant find any damaged to harness only 78k miles hopefully that was the issue i pray txs again

 

And just like that code 0304 and vsc are back on and rough idle and abs engaging at low speeds when comi g to a light how frequent coukd a ECM go bad and where its located to get correct part number ?

 

Odd only codes i have now are 0304 again but under abs cobe section only the ECM malfunction code came up this time

 

Damn again after i clear tge code with my scanner or battery disconnect the car runs near perfect and stops like new

But once the code is triggered 0304 it start idling slightly off and the abs upon stopping is being activated ???

Check injector ohm is at 13.9. 14. New coil denso and new plugs looked for damaged wires as far as i could or can and dont find any that have been tampered with ???

At wits end here only 78k miles 2007 rx350 ?

 

I dealt with very annoying misfiring and rough idle with my ebay fake denso clone ignition coils.
At least you are getting a misfire code(I wasn't) but the 0304 is kinda meaningless because it is a "generic" cylinder code and can be anything.

Please pull your fuel trims from your scanner and post them if you can.
A misfire will often be seen as elevated fuel trims.

Some check engine light conditions will trigger "limp mode" which limits how fast the car can go, and it "runs funny" and feels different from my experience and won't go into overdrive if I remember.
By pulling the battery terminal and clearing the code and your car magically runs good again tells me the problem is intermittent but slamming it in limp mode when it happens until the code clears.

It will take patience to get it sorted out as I can witness that intermittent electrical issues can be the most difficult issues to track down.
Hopefully you have your own scanner you can keep with you at all times to clear the code when it happens.

How's your estimated miles per gallon as shown in the info display? Does it seem lower than it should be?

 

Txs for the reply i thought 0304 was cylinder 4 abd code 0300 was general missfire i have a scanner but dont know which data to monitor shoet term long term fuel etc... it does have live read function with about 25 to 30 circuits bring monitored

It doesnt go into a true limp mode i can drive easily above 20 miles its at lower speeds it idles rough and upon stopping the abs engages odd as hell once code is cleared drives line brand new ??? For about 15 mins till the code returns ughhhhhhh next step is to take the glove box out and see if there anything wrong or screwy but i need to see tge ECM model number if thats my last resort

 

I would look at ABS first...

 

Abs sensors at the wheel or the actual control module where the brake lines go to

I can read abs codes initially 6 came up only now its the ECM module ?

 

sensors first... to see that they work, and work correctly