So, waiting on an ECU to come in I started messing around with trying to figure out WHY my car wouldn't go into overdrive. It wasn't throwing any codes. It would only go into overdrive sometimes and drop back into third gear randomly, and hunt back and fourth (on most cars thats another issue, not ours apparently). Days like today it wouldn't work at all.

I got below the transmission, all the connections were good but I went ahead and cleaned them. 0 Change

I noticed the TPS harness had some fraying by the connector on a pin (figuring it may be picking up possible resistance). I went ahead and replaced the connector. The car acceelerated more "cleanly" but still no change in over drive.

Then, going down the interstate at god knows 4k rpms I decided to engage my cruise once again, it seemed relevant in the past that sometimes it worked after using cruise - but I thought that was in my head and just a coincidence. So with my cruise control set at 60ish mph it dropped out. I pressed the cruise control button again, it went out. It may fury of anger at my car, I started pressing the cruise control like a full on retarded alcoholic step child and it stopped engaging at all...AHA!

I pulled over, once again like a full on retard, to the E. Lane and disconnected the cruise connector to the motor. Get on the interstate, what do you know...OVERDRIVE.

Now I kind of suspected this after looking through the FSM and seeing the O/D cut signal from the cruise control BUT I have also lost my speed sensitive power steering, it's always highway mode now.

I'm wondering if the ECU is to blame or if there is another module that has failed that the ECU is getting false information from now...which could explain my EGR issue as well (considering it's based on load, rpm, etc).

Cliff Notes: If you over drive isn't working, and you have no codes - UNPLUG THE CONNECTOR TO THE CRUISE CONTROL MOTOR.

 

Oh, yes, here's a picture...back to detailing the Porsche Panamara...

 

Nevermind, the piece of horse....s... is back to its normal routine of doing whatever the hell it wants to. I'm about to light my car on fire and send it the junk yard. Good god finding a 95 ECU has been crazy, and with me driving eight hours a day, waiting on Aliga to get the ECU is costing me about as much money as buying a brand new one from Lexus in GAS.

 

I've discovered that once the car has warmed up fully (I mean about a twenty mile trip) it'll start dropping into over drive like it's no big deal and last all day (pending the car stays warm).

Could the coolant temperature sensor be causing this?

 

Anyone? I see in the FSM the CTS is part of the shift pattern. I'm just going to go ahead and replace it.

 

I'm not sure about what exactly is going on in your SC, but I've read in my repair manual that if O/D isn't engaging problem would be shift solenoid.

 

From what I can tell there's two main shift solenoids - one would be the 1/2 solenoid the second would be 3/4 solenoid - but why would it shift into third jut fine? On another note, I let it warm up to full operating temperature before leaving today and it shfited flawlessley. I've got an oil leak over by the sensor from cam seal being done so I'm willing to bet oil has gotten inside the connector somehow and corroded it raising the resistance of the sensor.

 

That's also a possibility. 'Cause according to the manual, you also need to clean the connectors and test them for resistance. Well, it's clean everything first, check for resistance, then if nothing change the solenoids. That's how it goes in the manual I have downloaded.

 

Unfortunately that connector is a PITA to get to with my hands so I'll have to find a small person and let him do his thing to get in there.

 

Hey, what's up man. Any updates on this?

 

Bad VSS Capacitor

https://www.clublexus.com/forums/per...bad-ecu-2.html