Emissions/ SAI system

2004 AUDI A6
78,000 MILES
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COLLISION BOB
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  • 2 POSTS
Hi Everyone... Here it is: Car is a 04 A6Q w/2.7 BEL engine

1.) CEL on
2.) Scanned / 3 codes....#17862/ 17819/ 17831
3.) Checked circuit fuses, tested pump relay.... All tested good
4.) Checked for voltage at SAI pump, 12v at pump but pump inoperative
5.) Removed pump & took apart
6.) Pump was seized and burnt at motor brush locations/ housing w/small
amount of melt. Plastic brush holder in motor completely fried.
7.) Bought & installed new pump / cleared codes
8.) New pump failed within 50 miles
9.) Tested new pump. Isolated it ,applied 12v, inoperative
10.) Scanned system, same codes found


Notes: On engine shut down after initial test drive noticed SAI pump was
running with engine off. Thought this was odd.

Question: Would a bad exhaust gas temp sensor in bank #1 cause the OEM
pump to fry?
How do I test this sensor with a DVOM & what are the specs that
I need to look for?
Apr 21, 2013 at 9:07 AM
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ASEMASTER6371
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  • 52,796 POSTS
does this have a check valve for the exhaust?????

the pump may be failing from excessive pressure backing into the pump.

also, check the cat converter back pressure to be sure the engine is breathing out the back and not back to the pump

Roy
Apr 21, 2013 at 10:36 AM
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COLLISION BOB
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Hey Roy.
This engine uses three check valves in the SAI system. One check vavle is used to regualate vacuum. The other two are called combination valves :one for each bank of cylinders.
Thanx, C/Bob
Apr 21, 2013 at 1:30 PM
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ASEMASTER6371
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i would be looking at these valves allowing exhaust back to the pump

Roy
Apr 21, 2013 at 3:06 PM