OBD codes troubleshooting 98 Lexus LS 400

[M.Yasir]

Hi

Finally i managed to get the OBD II device (ELM 327), i am having a check engine light on this is what i am able to pull up with the device

I just wonder what in the world is turbine speed sensor!

 

 

 

 

[sha4000]

PO715 Turbine speed sensor is the one the transmission. I had this code pop up for years. The first time I took it to Lexus and they told me I needed  new transmission. I declined and took it to a indie and had the pan drained and refilled. Fast forward a couple of years and the code is still popping up  now and again so I do some research and find out there was a TSB out for the PO715 code which led to them changing the ECU. Technically it was an SSC ( Special Service Campaign ). Whether this is your issue or not I would check it out.

 

campaign-ssc-wl2-1998-gs400-ls400-sc400-ecm-replacement.pdf

LexusRecall.pdf

[M.Yasir]

Changing the ECU?! ..... also Craig this error code is eating up my fuel mileage again what bothers me more is the sluggish gear shift, when shifting from 2nd to 3rd it gives a good amount of jerk, but then again for this jerk i have a feeling that my transmission mounts must have been transformed into solid rocks rather than acting as a shock absorber

[sha4000]

My issue and the reason the SSC was put out was because the ECU was throwing this erroneous code even though there was nothing wrong. Your turbine speed sensor might very well be bad since it might be affecting the performance of the car.

[M.Yasir]

Do you have pictures of where exactly this sensor is located? i searched google but there are no images for 98 model...

[sha4000]

I have a pic somewhere on my computer but I'm at work right now. I'll look for it when I get home.

[M.Yasir]

No photo.... now the check light is coming on and going off ...... light off for 2 days comes back on .... kind of intermittent but with a prolonged duration

[Exhaustgases]

How is the ECT?  How are the o2 sensors?  Check fuel pressure and Maf. Fuel filter?

 

[sha4000]

Been kind of busy but here's a pdf that shows where the sensor is located.

http://lexus-doc.ru/ileaf/lex96rm/96rmsour/1996/96ls400r/di/at/cip0715.pdf

[92luxasls400]

I'm having problems with my 92 ls400 dieing when I stop at a light could this be the fuel filter 

[M.Yasir]

Now another code is being popped up........ here is the screenshot

[sha4000]

Seems to point to a transmission issue. Found this thread.

 

http://www.clublexus.com/forums/gs-2nd-gen-1998-2005/232357-need-help-on-some-check-engine-codes.html

 

[M.Yasir]

wow now i have more codes.... the whole car is shaking while shifting gear and also while cruising....

 

[M.Yasir]

It is getting frustrating now....

I saw a garage who will do the sensor replacement hand to hand ( without leaving the car in the garage for days)... i am planning to buy the following

1.) O2 sensors 4 Nos.

2.) Transmission sensor

will report back

[Exhaustgases]

Oh and the turbine is the input element to the transmission input shaft with in the torque converter. The pump is the element connected to the engine, then the stator is the element that directs the fluid flow into the turbine and its action creates the torque amplification, this happens at stopped and low vehicle speeds, as speed increases the stator starts to free wheel and torque amplification drops off, and then the torque converter clutch is applied and the whole torque converter is then bypassed and out of the picture for power flow to the transmission input shaft.

[M.Yasir]

Craig could you please search for that photo of the location of the transmission speed sensor

[sha4000]

I know in the picture that i had it was on the drivers side of the transmission. I have that side of the car on jack stands doing some work on the tie rods so I'll take a look to see if I can locate it tomorrow.

[M.Yasir]

Appreciate that

[M.Yasir]

Hi

Finally i managed to get the turbine speed sensor

And also i ordered Bosh O2 sensors from rockauto.com 

I have not installed these sensors & the speed sensor yet

But today morning i noticed that the CEL is flashing (while running the car) stops (when idling on a traffic light), i searched on some other forums that there could be a possibility of cylinder misfire

Or to be on the safer side should i buy all 8 spark plugs and wire set?

I will pull the OBD codes today again and will post a snapshot here

Any help would be appreciated

[sha4000]

When I was having the multiple cylinder misfire on one bank it turned out to be the oil control valve on that side.

[sha4000]

Yeah I know I have to address my oil pan leak lol.

[M.Yasir]

Hi all

Update: I tried to pull up the codes and wow

Well i dont know why all of a sudden everything is coming up.... first i will replace all the 4 O2 sensors and also the turbine speed sensor and will report back

[sha4000]

With all those misfires on the same bank you might want to check your oil control valve.

[M.Yasir]

Update:

First of all it had been 3 days since i procured all the parts and was just carrying them in my trunk finding an inexpensive garage to fix everything

Parts I bought

1. Denso Iridium spark plugs
2. AC cabin filter
3. Engine Oil 10W40- ELF
4. Transmission Oil- AC Delco T-III
5. Engine Oil Filter

Unfortunately in this part of the world when you go out to hunt for a reasonable garage it is just like finding a needle in the haystack since i cannot leave my car in the garage for n number of days

In short all garages here were asking huge amount of money along with "leave the car" statement

Anyway, i went to a petrol pump (we have shops named autopro for repairs) and asked about the price, they said since parts you are bringing we will take only labor charge which was very reasonable.

 

So in 2 hours mechanic was able to replace all the 8 spark plugs, engine oil & oil filter, unfortunately i was not able to replace the O2 sensors since the mechanic said "sir the drivers side one is very difficult i cannot do it, i can change the other 3 if you want" i replied no leave it i will go somewhere else, indeed its difficult on the drivers side

Also we were unable to replace the turbine speed sensor because of the following reason

1.) There is very tight space to take it out

2.) The bolt which holds the sensor is broken in my case

3.) The mammoth size transmission mount is in the way

 

Here the quality of work is extremely horrible, they will just replace the part and thats it nothing extra i.e. cleaning, they will not clean an inch on their own, the whole engine block is in extremely dirty state

Conclusion

The car runs great with power like new, no check engine light

 

[M.Yasir]

Hi

Please could somebody help here please on how i will replace the turbine speed sensor?