Secondary Air Pump Issues (Pin 4 Code 11)

[sytruong]

Hey guys, thank you in advance for your awesome responses. Places like this are so rare on the internet now a days, so I always feel I have to thank you, @gerryvz

So I'm chasing down a secondary air pump (smog pump) that doesn't work, thus (pin 4 code 11).

Here's what I know so far:

• LH module is a newer unit, I have no other issues and codes associated with it
• Fuses are good
• Relay for the secondary air pump has been replaced (relay E)
  • Relay E seemingly doesn't respond to 12V at pins 85/86 like other relays. I have tested 4 of them, and it's unlikely they're all bad...
  • According to @gsxr they may act differently
  • 
  • The recepticles in the relay box receive 12-14V at pins 85/86, pins 30 and 87 also have voltage when the car is running
  • (Are all 4 relays bad? That would be crazy)
• Secondary air injection unit (smog pump) runs with 12V is directly applied to it

So that's where I am at... I'm taking a look at these electronic valves on the passenger fender wall, and this is what I am getting. I've tried searching, but it's still difficult to decipher which is which, and I am not sure what behavior is normal, and how they work (can someone please explain? other posts have explained, but its difficult not knowing what each of these is called). Can someone please explain what I am getting? Picture attached. Thank you!

 

[gsxr]

Do you mean that you apply 12v to the relay when removed from the car, and it does not click? Even when polarity is reversed? That seems odd...

 

[sytruong]

Do you mean that you apply 12v to the relay when removed from the car, and it does not click? Even when polarity is reversed? That seems odd...

Yes that is correct, even to the battery. On all 4 I've tested!

https://www.benzworld.org/threads/126-820-20-26-green-relay-driving-me-insane.3117342/

The guy in this thread has the same issue. He claims he has tested multiple as well.

 

[gsxr]

Hmmm. I'd double-check the pin numbers. Maybe open one up and see if anything interesting is inside.

 

[sytruong]

I've run the same tests on these other common relays.



They click over in any polarity.

I've opened the green ones up and they have some computer chips inside, it looks rather complicated. I've even re-melted all the solder joints. Same thing.
Let me open it back up and post a picture. Even if it doesn't help my case, just for research purposes. I haven't found a picture online with these opened up yet.

 

[sytruong]

Here's the inside of this wretched thing. I've spent hours running voltage and continuity test this thing trying to figure out what each component does.

Heres what Ive learned

• Shows continuity on pin 30/87 when relay switch is manually engaged (normal)
• I apply voltage via battery to 85/86... We expect the same voltage across 30/87. (I know the picture doesn't show voltage properly applied, I couldn't do it with one hand and take a picture at the same time. But it illustrates what I did.) However, with the switch manually engaged, there is no voltage across 30/87!!!! Even though there's continuity across it!
• So if some electrical engineers can chime in, that would be welcome

 

[sytruong]

I'm so tempted to pop one of those silver relays in, but I feel like my computer is going to be cooked

 

[gsxr]

Wow - that is crazy stuff. I had no idea this relay was so complex.

Maybe @Klink knows something about this unicorn relay?

 

[gsxr]

ETM schematic implies it SHOULD function the same as any normal relay... however that seems to not be the case. I'm very confused.