Bovineplan

1. take your VIN and ask the dealer which ecu part number you have. Make sure you have the right part number in the car.

2. Check the ecu for a repair sticker. SIA adds a sealing sticker for warranty purposes. Most ecu repair places do the same. If no ecu repair sticker ON YOUR CORRECT ECU, you have a choice. 1. Chance the ecu is good abd rebuild tranny or 2. Send the ecu to confirm YOUR CORRECT ECU was repaired.

Unless you have records about which ecu was fixed you only know there are two differwnt ecus and the mechanic statement. For the $115 SIA charges, id sure do that first before rebuilding a trans or valve body.

LeX2K

Warranty seal stickers are illegal in the United States, they can't void any warranty based on a sticker.

Bovineplan

Thanks. Great add. But i dont care. They put a sticker on mine. you also added nothing to the rest of what i said that thr OP isnt sure which ecu he needs, which ecu was fixed.

But sure, the sticker isnt the warranty.

LeX2K

Then don't quote me if you don't care.

FlexnLexus

Thanks for that @Bovineplan . I’ll hit up the dealer tomorrow and ask what the serial number is, good to know.

alextv

You could also go Lexus parts online and put in your serial #.

FlexnLexus

I called the dealer and the ECU that’s installed in my car is the correct one, but it’s not the one that was repaired.

Took the car for a 30 mile drive on the freeway and it shifted perfectly fine with no CEL, it just says that the code is still pending. Very weird, so I plan on sending out the ECU for repair and or check to make sure that it’s ok.

LS430Lexus

Where are you going to send it? I have similar problem and am thinking about sending out ECU. Reviews on SIA are very mixed.

FlexnLexus

SIA since they do seem very reputable. If the ECU is ok, then they will send the ECU back to you and just charge a fee for inspecting it. That’s my plan at least for now.

Bovineplan

That is a good plan. This way you know ot was sent out. I recall listong the pending/active code as i think it points them to the right spot on the ecu to check.

Keep us updated.

FlexnLexus

Will do. 👌

alextv

A repair shop will find cold solder joints in ageing equipment even if it hasn't caused any problems yet. For every piece of equipment there are known areas to look at and solder to prevent future problems. Also hopefully common known suspected capacitors will be replaced at same time even if they are good. Repair shops generally have kits with all the parts in a bag to replace per equipment and they replace them all. This is a cheap repair that you want to future proof.

FlexnLexus

Do you think something else related to the ECU, such as other ECU engine component commands inside the circuit board can trigger a transmission code?

What is the other connectors that are off to the side below the ECU?. Is this another module?

StanVanDam

Repairing/replacing the valve body is step 3 of the diagnostic process for P0761. Step 1 is check for other DTCs (which I'm sure you've already done), Step 2 is replace shift solenoid valve S3 (which it looks like you've done already), so next is to ensure there are no foreign objects on each valve and that they operate smoothly.

Step 4 is inspect/replace the torque converter clutch, and if that doesn't solve it, step 5 is to replace the transmission, although I would say send your ECU to be repaired (not exchanged with a different one) before replacing the transmission.

FlexnLexus

I sent out the ECU to get looked at, I should hear back from SIAC sometime next week on what they find out.