ukfan4sure

Still unresolved. Car still acting up on this stupid problem. Now my wife won't even drive it! 5/8/08



First of all; thanks for letting me in the forums. I am a regular on Bimmerforums (3100 posts), but the Lexus scene is pretty new for me.

First, I purchased this RX for my wife about a year ago. It had relatively high mileage (92K) but the price was great, so I bit.

It's been a perfect car until about 4 weeks ago when it took a spell of an apparent mis-fire with the tach jumping erratically (no change in engine speed, though), the car stumbling several times, and eventually dying.

It threw a code (but it said something about the Bank 1 sensor) and the VSC light.

For two straight weeks, it ran like a Singer sewing machine; no problems, so I threw the PO codes away and I don't remember the exactly what they were. I tossed it up to bad gas.

But several days ago, it acted in the same way again. I took it over to the local parts store to get the codes again, but before I could get there, the lights cleared (would they still be stored in memory?).

Anyhow, now I began getting worried about this PITA intermittent situation with the wifey driving it.

Well, yesterday it did it again and this time it stranded her. Jumping, stumbling, erratic, wildly swinging tach with no engine speed change (like it's electrical in nature). It seems that the problem subsides if the car sits for a while as the last two times it has done it, the next day it runs fine. Geez!

Anyhow, my question is this: Is the extra lead off of the battery (covered in the looser plastic sleeve) for all of the electronics? Does it have a link fuse under all of that? I felt down the length of it and I think there must be something inside as it doesn't just feel like solid cable. Could that be where an intermittent/corrosion problem exists? Is there a cable harness I can remove and reconnect somewhere?

Before someone mentions it, the terminals are tight and clean on the battery.

I did several keyword searches here, but to no real avail except for the mention of an "oil sensor" possibility. Does that sound pausible for these events I am seeing?

Anyhow, thanks a lot. I hope this will be "paybacks" through another forum for all of the people I help from time to time on the "Bimmer" side of the automotive world. Lexus is a strange, new world to me! Ha!!

thomas1

I see you are on both sites, get us some codes and we will come up with ideas, could be Air fuel sensors, bad coil packs, dirty IAC control...who knows, go to the local auto parts store and get a read.

ukfan4sure

As posted on LOC, see below:

OK, I dug it out of the trash beside the computer desk (I forgot I had put them there), but I am worried that the codes are simply a secondary response to the real problem. I could be wrong.

P1350 VVT Sensor Circuit Malfunction Bank 2 -- Camshaft position sensor.

P0340 The PCM has determined that a malfunction exists in the electrical circuit for camshaft position sensor "A" (Bank 1 or single sensor).

salimshah

If I was to lay my finger on, it would be the cam-shaft position sensor. This sets timing and senses rpm.


Never discredit the readings, as that is what the ecu sees and reacts to. Skill is still needed in diagnosing the root cause.


Salim

thomas1

Lack of oil changes can cause that sensor to fail, but replacing it would be a fix. I swear someone else had that problem just recently either on this site or the LOC and the sensor indeed did fix the problem and was not expensive. The sensor is located on the left corner of the head right below the valve cover and right above the starter. The rear cylinder head is on the lef rear corner of the head. Turning the front wheels all the way to the right and taking the tire off the driver side will give you access to the connector.(this is for the camshaft position sensor)

Nad1370

Bank 2 (radiator side head)VVT controller is one of your problems.
This controller controls the advancing and retarding of the cam timing upon given load. If the controller is getting stuck one way and not returning, the vehicle will stumble and eventually die out.
VVT controller is activated by oil pressure and a signal from the ECU ot control timing changes.
How are you on your oil changes?

If your lucky it could just be a sticking VVT controller. (Easy to replace)

You also stated a P0340 code<---Camshaft position sensor circuit malfunction Bank 1 (firewall side head)
I not sure if this is somehow connected by the 1350 code. It could but why on bank 1 not bank 2? Must be another issue.

Since your Cel light went off. I believe it's an intermitent VVT controller problem since a bad CMPS with set a "hard" code.

Folowing up on what Salim said...
It's really hard to diagnose something over the net and w/out special tools to diagnose. It would be even harder to figure out at home.

This is just my take on it. Good luck.

ukfan4sure

Wow! Thanks to all of you! I appreciate your help and think you have steered me in some direction to look.

Thanks!

BTW, I don't know the history of the oil changes except for my own. I use Mobil 1 5w30 synthetic every 5-6K miles, so for 4 changes now.

Boy, don't you just LOVE the position of the friggin' oil filter?

salimshah

If there are two sensors, [one on each bank], and we are not discussing early life failure, I would suggest replacing both. My theory is that the sensors belong to the same lot in manufacturing and have been subjected to the same environment/condition, so if one fails the other would fail soon. A little preemptive but bot totally radical.

Salim

thomas1

Here is the price on camshaft position sensors:
http://www.trademotion.com/partlocat...00&catalogid=1