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180 Posts
Discussion Starter · #1 ·
2002 passat wagon 1.8 T Auto.

Also reported owner(previous) serviced Trans.. whatever that means.. I do plan to check the fluid level in the morning using proper technique. It is goes into gear fine but in first it feels like it is slipping. Planning for the worst but hoping it is just fluid. but doubtful

Also the recirculate button for the AC does noting?

The tailgait\trunk switch in the door pannel does nothing. Trunk switch under the latch works fine.

Any suggestions about any of the above greatly appreciated.

Other wise it is in great shape :p

· Registered
2001 Passat wagon; 2016 Golf Sportwagen
5,537 Posts
Regarding the transmission, can you find out whether they did a drain-and-fill or a full pan drop? I had trouble following a drain-and-fill, but resolved it with a full pan drop and filter replacement.

P0011 = camshaft position over-advanced
Pull the timing belt cover and see whether the cam and crank are properly aligned
If they are, have a look at the cam chain timing, as well.

P0411 = secondary air injection problem -- the air pumps and the combination valves, particularly the former, are known trouble spots

P0420 = low catalyst efficiency. Although this MAY indicate either a bad cat or a bad rear O2 sensor, it is more likely the byproduct of another problem. (Been there ... done that with my son's 2002 A4 1.8T AMB. Once we replaced a faulty injector, the P0420 went away for good, as well.)

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984 Posts
P0011 says timing advance is too high so I am guessing it is idling too high.

Catalyst warmup threshold is p0420 it could be a bad cat or a bad 02 sensor.

P0411 has something to do with your secondary air system

They could mean a pan drop and a fluid and filter change. But again not sure if you don't know lol

Does the button light up when you press it?

Wouldn't know about the trunk.

· Registered
180 Posts
Discussion Starter · #4 ·
The AC button does and the air is cool.. THe recirculate does not light up.

Idle seems fine at 800 RPM How do you diagnose if you have a bad injector? and which one it is ?

I believe that the transmission is something he attempted himself will check the fluid level first.

will check the timing since I will be putting a timing belt kit in it. Not sure if that was done yet or not. It is not worth the chance.
thanks all

· Registered
1,456 Posts
P0411 indicates SAIP (secondary air injection pump) insufficient flow. It's for emissions only, won't affect performance, so it's your last priority. But you should fix it, since it will keep the CEL on, which masks other problems. And if you have emissions testing, you'll have to fix it.

I need to do a full DIY on troubleshooting the SAIP, but here's the condensed version:

The SAIP is a high pressure blower that runs only 60 or 100 seconds (depending on engine) after a cold start (but not in freezing weather). It blows ambient air in to the exhaust upstream of the cat to heat the cat up faster (so it works sooner). The combi valve opens to admit this air to the exhaust stream.

  • SAIP: right front of car, near the ground
  • Combi valve(s): at rear of engine, vacuum operated, 1.8T has 1, V6 has 2
  • 373 relay: switches power to the blower, in ECM box (40A fuse there, too)
  • N112 solenoid: switches engine vacuum to open combi valve(s)

The ECM energizes N112 and the 373 relay. The SAIP should run and the combi should open. This lasts only 60 or 100 seconds after a cold start.

After the O[SUP]2[/SUP] sensors are warmed up and working, the ECM activates the SAIP system again briefly to verify its operation. The ECM looks for the O[SUP]2[/SUP] level to increase at the (pre cat?) O[SUP]2[/SUP] sensor(s) to verify the SAIP is working. If it doesn't see extra oxygen, it sets P0411 (and I believe a different code for the other O[SUP]2[/SUP] sensor in V6 engines). Because the ECM verifies SAIP operation this way, you can't just jumper something out to eliminate the code.

Common failures:
  • Bad 373 relay: it's almost undersized, so the contacts burn up, and the SAIP either doesn't run or keeps running. Easy fix, just plug in a new relay, most all our Passats are old enough to need it now.
  • Leaky vacuum hose prevents combi from opening, especially 2002 & earlier, whose hoses harden up (see my DIY in Info Base to change hoses)
  • Combi valve gets carboned up, sticks open, allowing some exhaust gases to flow to SAIP. Water condenses in SAIP, destroying it via corrosion or freezing.

The last one is the saddest, since the SAIP is expensive.

Hope that helps a bit, but work on the other codes first.
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