GX460 P2714 P0761 Ultimate Summary and Hope For A Fix Thread

[gsi18867]

Funny enough, my GX460 was getting less closed when I did my own fluid exchange as I overfilled it a bit. I took it later to have them properly adjust the fluid level and it had more codes after that point.

I say more codes as my current shifting issues are not as bad as others on this thread yet. Sport shifting solves 100% of our issues still at this point after 2 to 3 years. But with the overfill, we were getting less codes when we just didn’t sport shift, even when it was cooler temperatures in Colorado. I was just curious to test it after a full exchange.

Thanks for letting us know! Our overfill condition is really interesting. Yours after fill, mine after fill, mine from the dealership, poster above mentioning trans shop top off. And I think it’s related to outrunning piston leakage. I’ve been hoping changing fluid characteristics could help mitigate but that’s only going to go so far before causing problems elsewhere.

 

[StriderWolf]

Thanks for letting us know! Our overfill condition is really interesting. Yours after fill, mine after fill, mine from the dealership, poster above mentioning trans shop top off. And I think it’s related to outrunning piston leakage. I’ve been hoping changing fluid characteristics could help mitigate but that’s only going to go so far before causing problems elsewhere.

Interesting indeed… questions arise then on how much to overfill, does it hurt anything, etc. Makes me curious as to if it’s worth it just to a 1/2-1 qt. I wonder if it actually “helps” or protects anything other than assisting with pressure buildup or avoids as much leakage.

 

[gsi18867]

Interesting indeed… questions arise then on how much to overfill, does it hurt anything, etc. Makes me curious as to if it’s worth it just to a 1/2-1 qt. I wonder if it actually “helps” or protects anything other than assisting with pressure buildup or avoids as much leakage.

I don’t think straight trans fluid helps with leakage. To do that, the fluid would have to be above the to of the piston top and leakage could still occur with a pressure imbalance. I think it has more to do with the pump sucking a full column of fluid and no intermittent air while the leaked fluid returns to the filter inlet. That’s my theory, outrunning the leak under normal engine operation rather than revving it up to push volume. Air is going to compress a lot more than fluid, so making sure the pump never sees air is important.

In my case, reverse takes a lot higher pressure, so outrunning the leak is even harder, hence my viscosity increase through additives discussion to reduce leakage.

But how much is too much? 1 1/2 over doesn’t seem like too much right now. But here’s another idea: how about lowering the filter intake level?

 

[Acrad]

I thought there was one on fluid. Definitely could be wrong. Couple things here. My truck was sold by the same dealership 2X. The second as a certified truck. Possibly a third time at the auction. My truck was 1 1/2 QTs over filled when I got it. The Lexus service history has some real questionable notes about servicing the air pump when the owner complained about shifting issues. My truck doesn’t have an air pump. This was addressed multiply times while under warranty. There’s mention above of somebody taking their truck to a trans shop and had them tell him it was 1 1/2 QTs low after he checked fluid using FSM method.

I don't recall seeing any any TSBs on AT fluid levels over the years.

Air pump is probably the SAIP (Secondary Air Injection Pump)

Side note ...all 10-13 models have an open ended campaign to fix for free even if problem re-occurs

https://lexusgxor.com/_media/general:special_service_campaign_jlg.pdf

"2010-2013 GX 460 owners: Special Service Campaign (8.8.2019) for Air Injection Pumps and Air Switching Valves. Status: Remedy Available / Description: There is a possibility that moisture in the air may cause a filter in the vehicle emissions system to degrade. This degradation could cause damage to other parts of the vehicle emission system and illuminate the check engine light. REMEDY: On Customer Demand any authorized Lexus dealer will replace the filter in the air injection pump with one of an improved design and replace the air switching valves in the vehicle emissions system FREE OF CHARGE. The dealer will inspect the air injection pump for damage and may replace the air injection pump as needed FREE OF CHARGE. Year and mileage limits do not apply to this special service campaign."

 

[gsi18867]

I don't recall seeing any any TSBs on AT fluid levels over the years.

Air pump is probably the SAIP (Secondary Air Injection Pump)

Side note ...all 10-13 models have an open ended campaign to fix for free even if problem re-occurs

https://lexusgxor.com/_media/general:special_service_campaign_jlg.pdf

"2010-2013 GX 460 owners: Special Service Campaign (8.8.2019) for Air Injection Pumps and Air Switching Valves. Status: Remedy Available / Description: There is a possibility that moisture in the air may cause a filter in the vehicle emissions system to degrade. This degradation could cause damage to other parts of the vehicle emission system and illuminate the check engine light. REMEDY: On Customer Demand any authorized Lexus dealer will replace the filter in the air injection pump with one of an improved design and replace the air switching valves in the vehicle emissions system FREE OF CHARGE. The dealer will inspect the air injection pump for damage and may replace the air injection pump as needed FREE OF CHARGE. Year and mileage limits do not apply to this special service campaign."

Can you tell me where the air injection pump is? I’m pretty sure it was an option not on the base model. I have a base model. But my trucks air pump has been serviced multiple times, according to the Lexus records. I have never been through the emissions system, so if it’s there…

 

[Acrad]

You are probably thinking of the rear air suspension (RAHC) equipped models.

SAIP is part of the emission system. Diagram is in the link I posted. AIr pump is in the front right passenger side of engine compartment.

 

[evolute]

You are probably thinking of the rear air suspension (RAHC) equipped models.

SAIP is part of the emission system. Diagram is in the link I posted. AIr pump is in the front right passenger side of engine compartment.


View attachment 4108736

Take it apart and remove the foam filter and replace with the below and you will won’t have to worry any longer.

 

[Acrad]

Unfortunately ...sometimes the valves on exhaust fail due to corrosion from moisture and not the foam. The programming of SAIP on '14+ changed...as '10-'13 only runs at startup and not shutdown. I guess Lexus figured it was easier to pay out on a service campaign for repair on 10-13 models than to release an ECM update that would have allowed '14+ operation.

 

[gsi18867]

Take it apart and remove the foam filter and replace with the below and you will won’t have to worry any longer.

View attachment 4108769

I’ll pull the Lexus records tonight and post the entries about the air pump here.

 

[gsi18867]

I’ll pull the Lexus records tonight and post the entries about the air pump here.

Unfortunately ...sometimes the valves on exhaust fail due to corrosion from moisture and not the foam. The programming of SAIP on '14+ changed...as '10-'13 only runs at startup and not shutdown. I guess Lexus figured it was easier to pay out on a service campaign for repair on 10-13 models than to release an ECM update that would have allowed '14+ operation.

See below. It looks like it had two different air injection valve issues. And the final Lexus performed check was 1000 miles before I bought it. Dealership said everything was good. HA!

 

[PinkyPeePaw]

See below. It looks like it had two different air injection valve issues. And the final Lexus performed check was 1000 miles before I bought it. Dealership said everything was good. HA!

View attachment 4108963

 

[PinkyPeePaw]

New to the group here. Has anyone had a rebuild done with good a good outcome? My 2011 GX has both tranny codes I’ve been dealing with for 2 years now. Had the VB replaced and was good for 2 months then codes reappeared. 178K right now. If I drive in manual mode till the vehicle warms up it will not throw codes. I was quoted 4K for a rebuild out of a place in Austin TX. Problem seems to be between 3-4th gear. Has a hard time catching 4th.

 

[gsi18867]

I put another Qt of fluid in yesterday afternoon. That puts me 2 1/2 QTs over the level set using the level truck method. The difference is amazing. No delayed shifts. Reverse on demand when cold, full power. Reverse on demand after short trips (this was usually where I had no reverse at all or had to rev to 5K+). No codes (haven’t had any since changing the C1 accumulator).

Are these transmissions starved for fluid? Does adding a transmission cooler just give more capacity?

 

[gsi18867]

New to the group here. Has anyone had a rebuild done with good a good outcome? My 2011 GX has both tranny codes I’ve been dealing with for 2 years now. Had the VB replaced and was good for 2 months then codes reappeared. 178K right now. If I drive in manual mode till the vehicle warms up it will not throw codes. I was quoted 4K for a rebuild out of a place in Austin TX. Problem seems to be between 3-4th gear. Has a hard time

New to the group here. Has anyone had a rebuild done with good a good outcome? My 2011 GX has both tranny codes I’ve been dealing with for 2 years now. Had the VB replaced and was good for 2 months then codes reappeared. 178K right now. If I drive in manual mode till the vehicle warms up it will not throw codes. I was quoted 4K for a rebuild out of a place in Austin TX. Problem seems to be between 3-4th gear. Has a hard time catching 4th.

Manual shifting never worked for me. But I did have delays 3-4. One day it would never catch 4. Try putting in a qt of trans fluid.

 

[PinkyPeePaw]

Manual shifting never worked for me. But I did have delays 3-4. One day it would never catch 4. Try putting in a qt of trans fluid.

This is exactly what mine is doing! Thank you I’ll try adding fluid.

 

[gsi18867]

This is exactly what mine is doing! Thank you I’ll try adding fluid.

Any reverse problems?

 

[StriderWolf]

I put another Qt of fluid in yesterday afternoon. That puts me 2 1/2 QTs over the level set using the level truck method. The difference is amazing. No delayed shifts. Reverse on demand when cold, full power. Reverse on demand after short trips (this was usually where I had no reverse at all or had to rev to 5K+). No codes (haven’t had any since changing the C1 accumulator).

Are these transmissions starved for fluid? Does adding a transmission cooler just give more capacity?

Super interesting! It does confirm last year when I did the level method myself and left in likely over a court versus normal. Period. I did not get any codes for quite a while and had better shifting. However, on a really cold day, it did struggle and later at the Toyota shop I did have them bring it back to the correct level.

 

[gsi18867]

Super interesting! It does confirm last year when I did the level method myself and left in likely over a court versus normal. Period. I did not get any codes for quite a while and had better shifting. However, on a really cold day, it did struggle and later at the Toyota shop I did have them bring it back to the correct level.

What do you mean by “struggle”? Was there any improvement after they brought the level down? Did any adverse effects or codes return after they brought the level down?

I am considering lifting the front of my truck with 1 inch spacers. This will change the fluid level relative to the filter intake. May change dynamics

 

[PinkyPeePaw]

Any reverse problems?

Negative on that. Always get reverse whether cold or hot.

 

[StriderWolf]

What do you mean by “struggle”? Was there any improvement after they brought the level down? Did any adverse effects or codes return after they brought the level down?

I am considering lifting the front of my truck with 1 inch spacers. This will change the fluid level relative to the filter intake. May change dynamics

“struggle” in CO on colder days 20-40 F, the ATF takes longer to heat up and is assume expand. The struggle on mine is getting from 3 to 4th gear. This will flip a code if the ATF isn’t warmed up for 15 minutes. So I noticed this struggle more AFTER the Yota tech brought the level back to normal (dropped 1/2-1 Qt). I had more codes and 3-4 struggle earlier and more often.