A question on method to change the ATF on GS450h (3rd gen)

[zeczec]

Good day all.

I've been trying to correctly change my Transmission fluid on said car (after repairing the bearings on the electric aux pump of the tx). I am stuck on the temperature check bit. Does anyone know how to properly do it? There's a techstream method (which I've tried and failed with due to communication errors between laptop and car), and there's a method involving jumping 2 terminals of the OBD port.

I've researched the latter, and have gathered from the web that the method is (assumably) as follows:

1. Jump the 4 and 13 terminal on the OBD port

2. Switch car on. It will go into some sort of diagnostics mode.

3. Shift the transmission from P to S, then downshift to 1, then upshift all the way to 6, then shift to P, then D, then constantly shift from N to D holding each position for minimum 1.5 seconds for a total duration of minimum 6 seconds.

4. Remove the jump connection from the OBD.

5. Wait. Eventually both P and D on your dashboard should simultaneuously light up solid. That's when the temperature check is now complete, meaning the fluid is at the correct temperature for you to get beneath the car and open the overflow. Wait for the overflow to stop overflowing, close with new gasket. Job done.

Have I made any mistake? I have tried the above but P+D lighting up together never happened... and I waiting 5 mins, and in that time the engine even cut out to denote Battery charge cycle completion. Perhaps I'm not supposed to remove the jump at all until the very, very end?

 

[ColinBarber]

1 hour ago, zeczec said:

Have I made any mistake?

This is the procedure for the series IV, I assume it is the same for the series III.

 

[zeczec]

1 hour ago, ColinBarber said:

This is the procedure for the series IV, I assume it is the same for the series III.

 

Thanks for this Colin, I'm keen try to it first thing tomorrow. But a question comes to mind, when the D light goes off after having been on for 2 seconds, and I then shift it into P... is there some way to tell that I'm now at the correct temperature? Perhaps P+D come on together for my Series 3 - I'll have a go and see.

[ColinBarber]

34 minutes ago, zeczec said:

Perhaps P+D come on together for my Series 3 - I'll have a go and see.

The last sentence states the D will come on when at temp and blink if over temp. 

[Lwerewolf]

As I wrote somewhere else - make sure the engine idles (i.e. maintenance mode). You won't get the proper fluid level if the engine isn't idling either (1000rpm).

[zeczec]

Good news... the method stated on page 32 of this slideshow worked for me: https://slideplayer.com/slide/14432904/?utm_source=LexusOwnersClubUK&utm_medium=ForumLinks

It turns out that for the GS450h and LS600h, 3 terminals need to be jumped; 12, 13, and 4. Turn on car, shift to neutral, then shift between N and D constantly for about 1 second on each position for a total of at least 6 seconds, at which point you'll notice D's light on the dash staying on for 2 full seconds before disappearing. You are now in ATF temp check mode. Shift it to P, and pull out the jumps from the OBD. After a short while in addition to P being lit up, D will also light up - and that's your cue that the ATF is now at the correct temperature for you to open the overflow check plug and release the excess.

Thank God it worked out. Car drives beautifully again and shifts between MGS1 and MGS2 flawlessly.