2009 IS250 New Owner - Needs help . P00031 or perhaps, worse?

[pawly420]

 

 

I apologize for my new-ness and for just barging in.  I've never been a part of a forum, but with this Lexus, which I LOVE, I figure I am going to need all of your expertise to get this thing code free.  Yes, my check engine light, slip control light, tpms light and red triangle with "!"  all stay on, all the time.  

1. The TPMS are old and need replacing and reprogramming, so this is not my main concern.  

2. The other lights, I have been told by the big 3 auto parts places in town, are related to a P0031 code.  (upstream Bank 1 / Sensor 1 AFR Sensor heater low voltage) - checked the wiring, its good.  changed the AF sensor, still same problem.   NO real noticeable problems as a result of this condition, perhaps a little less fuel mileage than expected.   BUT I don't want my dash lit up like a Christmas tree either.  

3.  SO, I decide to get the mini vci J2534 cable and then have them install Techstream V16.00.017 on my laptop, because I wanted more information, plus really wanted to disable the DRLs.  undoubtedly I need a different version of techstream for the DRLs (v12 maybe?).  I digress.        When I run the Vehicle Diagnostic Report, below is what I get and I have no clue what to do with it besides start looking up things and checking for some bad connections or wiring possibly anywhere on the car.  (Because I'm just a guy, that cant afford to take it to Lexus and just have them fix it.)  Does any of this relate to the P0031 code the Auto stores are insisting is the problem?  Perhaps my sensor is good, but the harness  or wiring going to the sensor is bad?    

I know this is a ton of stuff, and again I apologize for barging in with all the thinking out loud.  I'm just looking for help, answers, direction, if any of you have any.  IF not, well, I completely understand, and thanks for your time and consideration anyway.

Code	Description	Current	Pending	History	Summary	Freeze Frame\
C1201	Engine/EV Control System Malfunction	X			Icon C	N
C1241	Low or High Power Supply Voltaae	X			lconC	N
C1439	Steerina Angle Sensor Initialization Incomplete	X			lconC	Y
U0073	Control Module Communication Bus Off	X			Icon C	N
U0123	Lost  Communication With Yaw Rate Sensor Module	X			Icon C	N
U0124	Lost  Communication With Lateral Acceleration Sensor Module	X			lconC	N
U0126	Lost Communication With Steering Angle Sensor                                                     Module	X	Icon C	y

Like I said, Any help will be much appreciated, and I do thank you for all your time, spent on this.  

Thanks, 

pawly

 

IMG_1475.heic

[RX400h]

Sometimes warning lights come on because battery voltage is starting to drop. Have you had your battery charged and load-tested?

[pawly420]

yes, I have checked the voltage, load tested, just about anything simple and that doesn't cost too much money, I have tried (e.g. gas cap) , but I am becoming more and more convinced that I have a bad ground or wire shortage  / bad connection that will require taking everything apart and probing every little wire, just because i don't understand how to check for voltage drops between main things, to indicate that it is there 

 

[RX400h]

Also check wiring that passes through your driver's door and into the engine bay for rubbing issues. There should not be too many ground connections. You may be able to find a location diagram on the internet. As you probably know, you should not be able to rotate a ground connection by hand.

[1stgenlexusgs300]

 

There was a service bulletin regarding the 2004-5 ES330 which may help you diagnose your troubles. One of the things mentioned was a faulty ground in the sensor wiring harness. Or a poor electrical connection due to what I’ve posted below about how the sensor interprets voltage.

https://www.autocodes.com/pdfview.php?pdflink=https://www.autocodes.com/uploads/lexus/EG003-05.pdf&titulo=2004-2005 Lexus ES 330 Factory Service Bulletin OBDII Code P0031

Also the sensor element is made of platinum-coated zirconia and includes an integrated heating element.
The zirconia element generates a small voltage when there is a large difference in the oxygen concentrations between the exhaust gas and outside air. The platinum coating amplifies this voltage generation.
The air-fuel ratio sensor is more efficient when heated. When the exhaust gas temperature is low, the sensor cannot generate useful voltage signals without supplementary heating. The ECM regulates supplementary heating using a duty-cycle approach to adjust the average current in the sensor heater element. If the heater current is outside the normal range, the signal transmitted by the air-fuel ratio sensor becomes inaccurate. As a result, the ECM is unable to regulate the air-fuel ratio properly.
When the current in the air-fuel ratio sensor heater is outside the normal operating range, the ECM interprets this as a malfunction in the sensor heater and stores a Diagnostic Trouble Code (DTC).

[pawly420]

thank you all for taking the time to post.  Due to things I've already tried, I  have basically resigned to the fact that it is faulty wiring of the ECM is bad.  So thank you for the insights on anything wiring related.  I am steady searching for a wiring diagram that shows the electrical that would encompass the  A/F sensors and O² sensors all the way back up to the junction box

Thanks

[pawly420]

so by happenstance, I was doing some wire routing through the center console (separate project).  But this required having to use the "Shift"  manual push button to put the car in gear in order to remove the console.   ( I know I should have disconnected the negative side terminal on the battery, but didn't since I wasn't doing any electrical work ).  However, upon putting it back together and with it still in neutral, with the parking brake applied, there were no lights that coded upon starting the car.  No "check engine" light, no "vsc" light.  (TPMS light, yes, but it is valid and they all 4 need replacing and programmed).  So, not even the red triangle "!" light. ...;  UNTIL, I reset the parking brake.  Once I released the parking brake, the lights came back.  I can repeat this process again and again, and they will stay cleared as long as the parking brake is set.  

Does this give any other ideas as to what might be going on?  Something to do with my shift locator?  Or parking brake?  

Just thought I'd share. 

Thanks.