Tom Rathjen

So….here is my latest problem with my 04 Cayenne: After performing four separate maintenance and repair items, I have begun getting a NEW check-engine light error code: P0413 “Secondary Air Injector Switching Valve A Circuit Open” (according to the generic reader at Advanced Auto Parts). I have been searching, and have not been able to find much more information out there on this P0413 code as specific to the Cayenne or VR6 engine.

I would not be surprised if I “disturbed” something while doing the other unrelated work, although I have searched and searched and have not been able to find anything broken, disconnected, or out of place. The first thing I did recently was replace the spark plugs. This seemed to go well. The second thing I did was change the oil and filter. Again, that seemed to go fine. The third thing I did was replace a “venturi tube” assembly which had broken, resulting in a vacuum leak that affected the brake performance. (See attached photo, and separate post.) And the most recent thing I did was replace the exhaust cam position sensor because of a P0017 error code (see separate post on that). Now….I don’t know exactly when this new P0413 error code began, because I’ve already had the CEL light on because of the P0017 code for quite a while. So this new code could have started after any one of these other work items, or completely independently, since I didn’t have the codes re-read until today after replacing the cam sensor a few days ago.

The only electrical connector that I knowingly disturbed during all this (except for the cam sensor connector, of course) was the one indicated on the photo below. It connects to a “t-socket” (p/n 94860513703). I had to disconnect this in order to remove and replace the venturi tube assembly. I can’t tell what this electrical connection does, because the “t-socket” appears to be a simple tube with no moving parts. Maybe it is a temp sensor? In any case, I did reconnect it, and it appears to be fine and intact.

I have searched some parts diagrams on-line for anything related to “secondary air injector”, and what I find (secondary air injection pump and associated lines and valves) do not appear to be included on my vehicle. Or if they are they are REALLY well hidden.

So, I fear I may end up at the dealer for this one (gasp). But any suggestions are welcome.

Oh yes, I forgot to mention: the vehicle is running just fine.

Thanks!

Slow Guy

Didn't someone else just post about SAI errors a couple of weeks ago?

Tom Rathjen

The only other SAI post in the cayenne forum I could find was from May, and it was a CayenneS (V8) and a different code (P0492), and did not seem applicable to my problem.

911SLOW

'04 Cayenne

Cayenne DME 7.1.1 P0413
OBD (II)

Secondary-air solenoid valve driver – open circuit

Diagnostic conditions
• Battery positive voltage between 10 V and 16 V
• Time after engine starts > 1 second


Possible cause of fault
1. Fuse F50 faulty (fuse carrier on left of dashboard)
2. Open circuit in voltage supply in secondary-air solenoid valve
3. Open circuit in ground supply in secondary-air solenoid valve
4. Secondary-air solenoid valve faulty (resistance too great)
5. DME control module faulty Affected pins DME control module plug A, pin 44, and pin 2 of secondary-air solenoid valve plug

Diagnosis/troubleshooting

1 Check fault memory
♦ Check whether fault
'P1182' is entered
Only fault 'P0413' is stored
Step 2
Repair wire running from battery
via fuse box and cut-off
connection KE 2 to secondary-
air solenoid valve plug
connection and correct the
cause of the fault if necessary

2 Check secondary air solenoid valve
♦ Disconnect secondary-
air solenoid valve
plug
♦ Visual inspection
♦ Measure resistance
in the secondary-air
solenoid valve
between pins 1 and 2
50 Ω to 60 Ω at 20°C
Step 3
Replace secondary-air solenoid valve

3 Check voltage supply for secondary air solenoid valve
♦ Switch on ignition
♦ Measure voltage between secondary air solenoid valve plug, pin 1, and ground
♦ Switch off ignition
Battery voltage
Step 4
Repair wire between voltage distributor S 10 MOVO and secondary-air solenoid valve and correct the cause of the fault if necessary

4 Check wire for continuity
♦ Pull off plug A on
DME control module
♦ Visual inspection
♦ Measure resistance
between DME control
module plug A,
pin 44, and pin 2 of
secondary-air solenoid
valve plug
< 2 Ω
Step 5
Repair wire and correct the
cause of the fault if necessary

5 Check whether additional faults are entered Step 6 Work through faults in
accordance with instructions

6 Replace DME control module in order to check it out
If the fault is still present, the original control module is in working order

Tom Rathjen

Hmmm. My model/year (Cayenne V6, 2004) does not have a fuse 50. (There is a fuse slot #50, but it is empty. And the owner's manual confirms it should be an empty slot.) And after two hours of crawling around the engine yesterday, I could not find anything resembling an air pump or solenoid valve for an SAI system. So I am still stumped.

Tom Rathjen

Well, I messed something up now.

After several more hours in the garage and time researching on-line schematics, I finally determined the details of the secondary air injection system that I have on my V6. See schematic below. The air pump is down near the front right wheel well, and there is a vacuum-driven "cutoff valve" up on the rear right side of the engine. The vacuum line connected to this cutoff valve runs down to the left side of the engine below the intake to a "change over valve" See the second schematic. So, my guess is that the P0413 code is associated with this change over valve (which is an electrically driven solenoid valve), which is connected to the SAI cutoff valve (the change over valve on the left in the schematic).

So....I proceeded to troubleshooting, using the steps above as a guide. First, I checked every single fuse in the engine compartment and the dashboard (since my car doesn't have a fuse #50, I was not sure which fuse might possibly be associated with that change over solenoid valve). I found no bad fuses. Then, I checked if the vacuum line that runs from the intake to those two change over valves (and thus provides the vacuum source) held a vacuum using a mitivac. It did. Then, I disconnected the connectors from both change over valves (very difficult, without removing other engine parts), and attempted to check the continuity across the valve contacts to see if the valves are good. I was not able to complete this step, because there just was not enough room to get multimeter leads down to the valve contacts. So...I decided to give up until another day, when I could spend more time removing parts around those valves to provide enough access to test them.

So, I put everything back together, and tried starting the car. And now something (or more than one thing) is badly wrong. The idle was very rough, initially with surges. There were knocking sounds. The PSM failure light came on. I have no idea what I did. I checked and rechecked that I reconnected everything and reinstalled all the fuses properly, and everything looks right. But something very bad happened.

Starting to wish I had just taken it in to the dealer for the 0413 code. Now I can't even drive it.

cordsig79

Howdy, I own a 2006 V6.....had replaced plugs recently and suffered a vacuum leak that was making the engine rev high and oil warning light pop on. I took it to just a local shop and did a smoke test and detected the vacuum leak and replaced the worn pipe. It makes the engine run like ****e and gauges puke due to lost oil pressure. ITS PROBABLY ANOTHER LEAK....

I had about a month ago the 4wd failure PSM warining pop up......read on here its probably a battery going or the valve replacement that happens alot on these transmissions. Still need to replace it.

Now I am getting a CEL for 0431 and 0421 bank 1 and bank 2 failures.....air/fuel mixture too rich. So I am trying to replace oxygen upstream and then downstream this weekend at a local shop in Austin.

I am wondering if by chance you have an issue on spark plugs and further tearing it down is causing issues...some of which could be iginition system related and battery related.

Lets brain storm, as I am sure I will see an issue such as this soon...vacuum leak, when did you last replace battery, recheck the spark plugs and pencil coils for fitment and connectivity, and then take it to dealer.

Tom Rathjen

Hello. I have been out of town for a couple weeks, so just getting back to my Cayenne issues.

I recovered from the serious problem with engine knocking, PSM light, and very rough running that occured after I was doing some troubleshooting on the P0413 error code. It turned out to be a bad #7 fuse. Apparently, during the process of checking every single fuse, this one must have been damaged while reinstalling it. So, after replacing that fuse, and cycling power to the control unit by removing and reinstalling its fuse, everything ran fine again and the car drives great and no more PSM light. The CEL did come back on, however, and now I am getting two codes: P0413 (the one I was already chasing), and now P0864 which I have never seen before: "Transmission Control Module Communications Circuit Range Performance". Car is running great, so I am really getting frustrated with these darn codes multiplying every time I touch it.

I did buy a new "change over valve" for the P0413 problem, since it was only about $20, but I have not installed it yet since now I am worried about this new P0864 code which I could not find much info for on-line. I am close to giving up and going to the dearler. (But darn it, the car is running great!)

Tom Rathjen

I went ahead and installed the new change over valve. The old valve tested fine. Went back to the auto parts store and had the codes read again, and this time only got P0413. So maybe that P0864 code was something left over from my screw ups on 11/27, and is gone now since I had the codes reset this morning. So that's good. But....still not making progress on solving the 0413 code.

cordsig79

Tom, I would go to a battery store or measure the CCA on your own battery. If its below 700, you will get errors that are odd, as power is not properly getting to places and tripping the warning indicator thresholds.

If you go to Batteries plus near you. Manassas VA 10689 Sudley Manor Dr 703.330.7007. They should be able to help.....and fyi. The battery replacement they have, well there is one that is 840 CCA and 20 dollars cheaper and the exact OEM dimensions. I can dig up the exact Rayovac serial code later....

I replaced my battery, no more error codes on catalysty or rough idles...........and I just did the brakes too.

When you replace the battery you will find the Ground wire, which you can unhook for 120 seconds, and it does a hard restart on the computer, tripping back any errors that fired.

Tom Rathjen

Problem solved!!

I appreciate the suggestion about the battery, but that wasn’t the problem. Actually, it is a pretty new battery.

In short, but problem turned out to be that fuse #50 was not installed. (Which, of course, was 911SLOW’s suggestion back on 11/26.) So here is the full story of what happened:

I believe it all started when I replaced that “venturi tube”. To do this, I had disconnect the connector on that “T-Socket” (see picture), which it turns out is really a crankcase ventilation heater. Well, this connector is related to the change-over solenoid valve for the secondary air injection system, in that the wires from both the valve and heater join before going to terminal 8 on connector K6 (which in turn connects to fuse #50 and +12V). So….I believe the error code was first triggered with I had to briefly run the car while this crankcase ventilation heater was disconnected (because I had to move the car before I had installed the new venturi tube). This code persisted after I had completed installing the new venturi tube and had reconnected everything, as I did not go to autozone to have all codes reset. Then….in the process of troubleshooting, I pulled every single fuse to test them, and reinstalled them PER THE OWNERS MANUAL THAT CAME WITH THIS CAR. And, that owners manual shows an empty slot #50, and instead shows a 10A fuse in slot #48. And I believed this to be correct. After finally getting a hold of actual wiring schematics for the car, and testing continuity from the computer to the change-over valve to the K2 and K6 connectors and finally to the fuse panel, I discovered that indeed fuse #50 is for the secondary air injection change over valve and the crankcase ventilation heater. And there is nothing connected to fuse #48. (The book said “parking heater”, which I have no idea what that is. But because the book said there should be one in #48, it explains why I did not end up with one extra fuse when I replaced them all, which would have been a big clue.) So, with the 10A fuse properly moved from 48 to 50, and clearing the codes, the CEL has remained off. Yea!

I did discover a couple of great resources during all this which might be helpful to others. I discovered that Automotix.net has all of the schematics for the Cayenne available on-line for a modest fee (about $13 for 180 days access, or cheaper for shorter access). This really helped in understanding it all and finding the discrepancy between the owner’s manual and reality. Also, for a mere $15 I found an ODBII reader on Amazon for reading and clearing the fault codes. OK, the cheapest $15 one is pretty limited. But it does read and clear just fine. And that price was well worth it as it saved me multiple trips to autozone for reading and resetting while I tried various things. Very handy to have.

So….I’m done with this problem. Of course, I wish I had just put a darn fuse in slot #50 right at the start, but it is nice to have gotten in deep enough to really understand what was going on. Now all I have to do is put all the engine bay coverings back on, etc. Thanks for all the suggestions!

Slow Guy

Congrats. That was a real challenge!

zzzx990

it happened to me. I got P0431 and the F50 should be empty according to the manual. I put a 10 Amp there and the code was gone. also found a typo on the manual too. lol

Slow Guy

Just as an FYI, on a '06 CS (V8)

Left side (driver's) fuse panel:
I have a 10 A fuse in slot #50, in manual it's stated for: "Heating Pipe Ventilation"

Right side (passenger's) fuse panel:
empty slot in panel and stated as empty in the manual

Hopefully if I ever have an electrical problem I will remember the tips in this thread and verify the fuse locations in the manual are correct first.

Borntovin

My car stopped at a traffic signal in the middle of the road, the only indicator that I can remember was that Radio died few seconds before that. It happened to because of blown fuse 36 for ECM, PSM and other main modules. This is of great help , check your fuses before panicking and getting your car towed.

After fixing it , I checked each fuse by taking and putting it back. I might have done a same mistake of following the owner manual , for fuse schematic. I have a PSM failure workshop error and CEL with p0102 code. I just put a 10a fuse in slot 50 on left driver side, will test drive tomorrow and see if it fixes the issue. Will update after that.