GX470 Trouble Codes (1 Viewer)

[bennysc]

Having some out of the blue issues with our 2006 GX470.

Yesterday, the wife noticed a loud fan noise at start up. I checked it out myself, and on a cold start, some sort of secondary fan (maybe the electric one the oil cooler?) is making the noise.

Today at start up the noise returned and we got some trouble codes.

P1441 and P1445, which appear to be releated to the valves and vacuum lines for the evaporation system.

Also, at the same time, all of the traction control warning lights appeared on the dash (no VSC, skid control, etc)

These all appeared the same time, so I assume they are related to the same issue.

I am going to dig into it tomorrow, but was wondering if anyone has any suggestions before I head down the wrong paths.

Thanks!

 

[bennysc]

After some more reading tonight, it looks like the air pump may be failing, thus the noise at start up.

Doest sound like fun - it involves removing the intake manifold.

Looks like tundras have this problem.

Anyone dealt with this with a 120 or 100 series 2uz-fe?

 

[vwluv10338]

P1441 Evaporative Emission (EVAP) System Flow During Non-Purge Chevrolet Only
P1441 Evaporative Emission (EVAP) System Flow During Non-Purge Oldsmobile Only
P1445 Purge Flow Sensor Circuit High Input

A quick google shows this for your codes. That is the evap system not the air injection system that I think you are talking about. I dont know about the Tundra guys but in the 7 years I have been with Lexus I have never seen an injection pump go bad. The TRAC lights and all that always come on with the CEL.

 

[bennysc]

Here is what is in the FSM for a 2UZ-FE 4Runner:

P1441 Stuck Open in Secondary Air Injection Vacuum Switching Valve Bank 1
1. VSV for air
injection system
(bank 1)
2. No. 2 air switching
valve (bank 1)
3. VSV for air
injection system
(bank 1)
4. ECM
Comes on DTC stored ES-304

P1445 Stuck Close in Secondary Air Injection Vacuum Switching Valve Bank 2
1. VSV for air
injection system
circuit (bank 2)
2. Vacuum hose
(VSV for air injection
system - No. 2 air
switching valve)
3. Air injection pipe
(No. 2 air switching
valve - exhaust
manifold)
4. No. 2 air switching
valve (bank 2)
5. VSV for air
injection system
(bank 2)
6. ECM
Comes on DTC stored ES-318

The noise from the fan is what I am concerned about. Is it possible the valving could be allowing the air-flow from the pump to make noise?

 

[vwluv10338]

Honestly, I would have to research it. I have never seen one fail. According to those codes it sounds like a stuck VSV but I guess there are two, one for each bank? If there are two then both of them failing at the same time seems strange and unlikely. If I am not mistaken the secondary air is an electric pump so I'm not sure about the noise. Sorry I cant be more help. Honestly, I see the same issues over and over in the GX and rarely does anything else go wrong but there is a first time for everything I guess.

 

[bennysc]

Well the "first time" has an uncanny ability to happen to me.

The air pump itself is bad, it appears to have bad bearings, and the vanes of the actual blade have broken off.

Im guessing those made their way to the VSV bank 2 valves and have those clogged up.

Not looking forward to buying a $900 pump - it just isn't that complex of a part.

Ill need to be creative.

 

[bennysc]

I stumbled upon a post on the Tundra Solutions board, where someone mentioned the pump looked a lot like a pump they had replaced on some sort of GM product.

I did a little digging and found several new and re-manufactured units that fit various GM cars.

I purchased a Dorman pn #306-010.

It is the EXACT same pump, with the exception of the electrical connection, which I can use from the old one and splice it in.

This once cost me $118, not $1000 from Toyota. I am normally a huge fan on staying OEM, but that is crazy.

 

[bennysc]

Further along on the repair....

Replaced the pump and reassembled everything, only to have another trouble code appear. #1441

I tore into it again awaiting the inevitable realization that I would have to remove the bank 2 valves

2 frustrating nights later, I was finally able to get the water bypass and valve assembly out tonight by cutting the rigid air tubes. I intend to replace them with flexible high-temp rubber or silicon hoses.

Once I was able to dig into them, I discovered pieces of the original damaged air pump fan vanes had migrated down the valves and was preventing them from completely closing (the exact trouble code issue).

Now that those appear to be clear, no other parts of this system remain untouched, so knock on wood, it should be good to go.

Only casualty so far is that I damaged the female connector on the water temperature sensor. I will have to rig a fix for that.

What a frustrating repair this has been - but I am fully appreciative of dealers charging upwards of $2500 - $4000 for this repair simply due the labor.

 

[bennysc]

Well now i have a coolant leak...

 

[KillerPea]

The long and short of it is: The pump comes apart, and the plastic fins from the pump then blow into and interfere with everything downstream in the system, eventually melting in and sticking the last set of mechanical valves. I suppose there is a chance that one could replace the air injection pump the very first time it makes noise, but after that, its almost mandatory to replace everything

 

[kjohnson129]

Just had this issue come up on my 4runner. I realize it's an old thread, but do you have a link to any of the info on how to replace it? Thanks.