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It can be cleaned. Electrical contact cleaning spray works in tight spaces.
 

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It can be cleaned. Electrical contact cleaning spray works in tight spaces.
Electrical contact cleaning spray won't remove carbon tracking if it is burnt into the plastic.
His problem is not a connection issue.
 

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The diode or resistor in relays is across the coil to protect the switching circuit (ECU), from high voltage when the magnetic field collapses.
You're probably right that the ECU is more sensitive to voltage spikes and that is the real reason the resistor is there but it also prevents arcing across the relay contacts. In any case, the resistor (or diode) provides a low impedance path for the coil current to dissipate. Since the impedance is low, the voltage spike is low as well, since V = IR. This both prevents a voltage spike into the ECU output driver (also low impedance I would assume) and prevents arcing since the voltage across the contacts is limited.
 

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A resistor or diode across the coil, has no effect on the contacts.
If you want to protect the contacts from arcing, you could connect a varistor across the contacts.
A resistor or diode across the contacts would apply continuous voltage to the SAIP.
 

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Discussion Starter #26
Update:
Put another 1,000 miles on the car and the problem just refuses to fix itself 🤪, who would have guessed?
SAIP is still running whenever it wants for as long as it wants. Only while the car itself is running, though.

I took a look-see at the spot where the relay is plugged in and it looks pretty clean, so that's probably not the issue. I must have just bought the wrong relay.

OP, what is the number on the top of the relay? I can check the ones I have and ship it to you so you have the right one in there...
Hey VAGguy, you don't have a spare 373 (28/99) relay do you? I'm happy to pay for one.

Or if anyone can point me to which relay to buy online, I'd appreciate it. Mine says "8D0 951 253A" on the side, but I'm reading somewhere that was replaced by a 4H0... part #.

This one:

has me a bit concerned to drop $30 plus shipping because what I can tell from the picture, it looks like the numbers near the posts don't correspond the diagram on the side in the same manner that numbers correspond on the old relay I have sitting in front of me. Been a long day, I might just be too drowsy and reading things incorrectly, but I'd appreciate anyone who can point me in the right direction.

Just did an oil change, refilled wiper fluid, put on new front turn signals, changed low beam and brake bulbs. I'm feeling like we're about to take down this gremlin once and for all, It's exciting. It'll be the first time in 5 months that I've got no warning lights on the dash and no functional issues with my $2,000 beater.
 

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That’s about the only one I don’t have



I’d go to my local junkyard, but preparing to go out of town. If I make it over there, I’ll let you know.

Sent from my iPhone using Tapatalk
 

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Did you try a new relay ?
Did the same problem exist with the new relay installed ?

If you answered YES to the above questions, there are only 2 other possibilities.
Check the Blue/Grey wire from the relay to the ECU. Check for an intermittent short to another wire or ground.
 

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The newer VW part number is 4H0 951 253 A, but $34.20 msrp. ECS sells it for $21.xx and lists some less spendy alternatives.

You can also use Panasonic CB1A-R-12V from Mouser Electronics or Digikey, $5.30 plus shipping. This relay has the internal surge suppression resistor across the coil like the VW relay (the R in the part number).

Mouser (www.mouser.com) and Digikey (www.digikey.com) are both large electronics distributors. Just for fun, see how many CR2032 batteries they have in stock... (but beware that most batteries require ground shipping).
 

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you say in post # 26 ,"SAIP is still running whenever it wants for as long as it wants" If I read this correctly do you mean the pump is coming on randomly and running for an arbitrary length of time while you are driving? Please clarify?
 

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Discussion Starter #32
Thanks VAGguy, I appreciate the offer anyway! Don't go out of your way for me!
I'll try and go with one of these recommendations online ^^

I'm overwhelmed by the number of people willing to offer advice or even a spare part. This forum is truly great!

Did you try a new relay ?
Did the same problem exist with the new relay installed ?
I tried a new relay but it probably was the wrong type.
Old relay installed = SAIP never turned on at all, CEL came on and code pulled at autozone said P0411.
New relay installed = SAIP can be heard working for the duration of the drive, but not during every drive. CEL remains.

Thanks for the tip Fresco, I'll try one of those Panasonics next.

Cchief, I hope this post clarifies my issue for you. More or less what you described, but seems to last for the entire drive.
 

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Discussion Starter #33
UPDATE :

-Ok, I threw in one of these little guys that I got from Mouser :
100243

-Back to square one, SAIP is never heard running. CEL is still on.

-Following Tomvw's advice:

Check the Blue/Grey wire from the relay to the ECU. Check for an intermittent short to another wire or ground.
-I popped out the relay and can only see a small length of the blue/grey wire, however it looks like new. I reached under the relay to run my finger along the wire, and noticed that when the wire is touched, the contact that connects to the relay's left-most post (when facing car from front) is VERY loose, wiggles and moves up and down.

-Could this be an issue? This little wiggly, metal doo-hicky is supposed to be where post 85 plugs in like so:
100246

100245


-If it's a big deal, I'll look to replace that plug.
-If it's not a big deal, I'm planning to take an afternoon to try and move/remove whatever is blocking me from visually inspecting the entire blue/grey wire. Then it will be on to learning about " intermittent short to another wire or ground" and how to find them.

-Let me know if I'm doing anything glaringly wrong, guys. I appreciate your help as always.
 

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I doubt that's the problem. The metal receptacle parts that the relay plugs into are often loose as they just sort of snap into the plastic housing and are loosely held there. As long as the relay prongs engage the receptacles so the relay plugs in, any looseness isn't a problem and actually makes installation and manufacturing easier.

I didn't read the whole thread but to check for intermittent short to ground, you'll need an multi-meter. Set it to read ohms or to beep when resistance = 0 (most will do that) and then put one probe end on the plug in question and the other probe end on a known good ground (eg the body of the car). Then jiggle the blue/grey wire or whatever wire you are testing to see if it ever shows 0 ohms (or beeps if set to that mode). The procedure is the same for testing for a short to any wire except you would substitute the other wire for the ground. You are basically checking whether the blue/grey wire ever makes contact with either ground or some other wire.

Edit to add: Some movement of the female plug is normal but if there is so much movement that the plug could touch an adjacent plug that could cause a short to another wire. It's hard to quantify but I'd say a little movement is fine, but if the female plug seems like it's just hanging there or isn't supported at all, that could be a problem. In that case, use the multi-meter to check to see if any of the plugs ever touch each other, they shouldn't.
 

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If that wire is loose when the relay is plugged in, it is a problem.
This would indicate a bad wire connection to the socket or a bad connection between the relay and its socket.
 

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Discussion Starter #36
Thanks for the tips Iowegian, I'll pull out my multimeter this afternoon.

If that wire is loose when the relay is plugged in, it is a problem.
This would indicate a bad wire connection to the socket or a bad connection between the relay and its socket.
Ok, from what I can tell the actual (copper?) socket makes direct contact with the relay when I plug it in. I'll look extra close to make sure there's a good connection between the wire and the socket while I'm doing my multimeter business today.
 

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Discussion Starter #37
UPDATE:

I took my multimeter out, opened the box and measured ohms between the wiggly socket and the frame of the car. Multimeter read "1" on every setting, which as I understand it means the two leads never completed a circuit.

I checked between the wiggly socket and the socket where the opposite relay prong wold go - same results. Which is good?

So this wiggly socket part isn't shorting out on the car frame or the wire opposite it. Now I'm stumped. Do I check resistance between every socket and then the car frame?

RECAP:

-SAIP does not run at all with original 373 relay or replacement relay with resistor (Panasonic CB1A-R-12V).
-SAIP runs, every now and then for entire drive when wrong 40A relay is installed.
-Car shows CEL non-stop and code pulled at autozone is P0411.

So, the issue is electrical, correct? A certain amount of power is not getting through the appropriate relay to turn the SAIP on for the appropriate amount of time and sequence? Meaning the likely culprit is some fuzziness between the ECU and the relay, therefore Mr. blue/grey wire is our next suspect?

Let me know if I'm tearing my hair out for the wrong reasons. At least it's not an issue that prevents the car from running.
 

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Don't pull your hair out just yet.

Is the blue/gray wire physically attached to the metal part in the relay socket? If so, it's probably ok. The other end of that wire is at the ECM, just centimeters away (it's a German car, after all).

Note that the SAIP will only run on a cold start if the coolant temperature is below 31°F/91°C (1.8T) or 35°C/95°F (V6). Hotter than that, no SAIP.

I don't recall if you had a "ground" code for this relay, but that code can be deceiving--the full text is "ground or open circuit." The ECM monitors the voltage on its outputs. With the relay plugged in and key on, a tiny current will flow through the relay coil and "pull" the voltage on the ECM output (the blue/gray wire) up to ~12V. If the ECM sees less than 1 volt or so, it sets the code--it can't distinguish between an unplugged relay, broken wire, failure of the +12V on terminal 86, or a hard ground on the output. But if there really were a ground on the blue/gray wire, the relay coil would be energized any time the key was on, thus causing the SAIP to run.

I'd do this:
1) turn the key on (don't start the engine) and measure voltage between relay socket terminal 86 and ground. Should be ~12V. I doubt this is the problem.
2) if you can round up a piece of small gauge stranded wire, stick it in terminal 85 (with the blue/gray wire) and plug the relay in. Now, turn the key on (again, no start), then touch the small wire to ground for a few seconds. The relay should energize and the SAIP run. That proves the relay and SAIP both work.

You'll have to allow the car to go through a real cold start--if the weather isn't too hot. If you're in Phoenix, the coolant may never get cool, even enough overnight, until September.

If it is cool enough, the SAIP will run the prescribed time on cold start. A mile or two later, when you're at idle (stop sign, etc), it will run again--that's when the CEL will clear, like magic.
 

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Do you have VCDS? There may be a way to engage the SAIP manually via VCDS which could make trouble-shooting a bit quicker, since as FrescoGreen01.5 said, the SAIP only operates under certain conditions and for a fairly short time.
 
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