[fourteenyears]

Hey everyone

Car is throwing P0411 (Secondary Air Injection System Incorrect Flow Detected)

The problem is that there is zero voltage to the combi valve vacuum solenoid on cold start. SAIP had seized up and I replaced it. (Yes I replaced the pump rivets with screws!) All vacuum lines are good. If I pull the air pump hose off the air box after a cold start while the pump is running, I can hear the pump but get zero flow / suction on the hose. But if I jumper the plug on the combi valve solenoid, the combi valve opens and I get suction on the intake side of the SAIP.

What immediately preceeded this mess was a premature timing belt failure (80k miles) and resultant grenading of the valve train. Motor was pulled for TB replacement and head rebuild. P0411 came up a short while later. Long story but taking it back to the same shop is not an option, I'm stuck fixing it myself.

So what fuses, plugs, etc might cause a dead harness to the combi valve solenoid? And what is the color code for the wires to that solenoid, so I can check whether any plugs were switched around?

Thanks!

David

2001 1.8T

 

[red99]

The connections are as follows:

pin 1, blue-yellow, to ground
pin 2, brown-yellow, to pin 9 of 121 pin ECM connector

So the solenoid gets its power directly from the ECM. I would say to check resistance between pin 1 and ground. If that is 0, look for a break in the brown-yellow wire.

 

[fourteenyears]

Awesome, thanks man. I'll check BL/Y to ground and also output on pin 9. Aggravated by the whole SAIP system... if my fiancee weren't so freaked by the CEL, I'd rip that pump out.

Thanks again!

 

[fourteenyears]

Success!

Wanted to follow up on this thread for posterity, as I can imagine it happening to someone else. Problem ended up being that the electrical harness to the combi valve vacuum solenoid was swapped with the BOV solenoid harness. Plugs are identical and within easy swapping range. Mechanic put them back wrong after head rebuild, resulted in burned-up SAI pump. Plugs swapped back, $50 ebay SAI, CEL off, back in business.