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Code PO412??? PO410???

Cadillac Rob

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My 2000 DTS was giving me the PO412 code so I started by investigating the air pumps. I found both of them doubling as aquariums. So I'm getting the delco TSB replacements with the updated inlet snorkels that snap into the inner fender wells. This should correct the problem of them taking unneeded baths. But everything I'm reading on here is saying the code for the pumps themselves is PO410. Does my PO412 code mean the check valves are shot from this water intrusion? Or a vacuum solenoid is also an issue? I need to correct said problem to pass inspection. Can anyone give me any feedback on this dilemma? Thank You from Beantown.

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P0410 Secondary Air Injection (AIR) System

P0412 Secondary Air Injection (AIR) Solenoid Relay Control Circuit Bank 1

The P0412 code means that the relay for Bank 1 isn't connected or the relay is bad. This is an electrical problem. I would attack this as the highest priority because if the relay isn't working the PCM will probably throw the P0410 code too. A non-functioning relay is probably what happened to allow the pump itself to fill up with condensation. You might also check the intake hose to the AIR to make sure that it isn't off or broken. It's possible that if the relay, its wiring, and its connector are all OK and the pump is dried out that everything will be OK.

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Some versions actually have 2 different air pumps. One on the left and one on the right. My 2001 only has one on the drivers side.

These pumps sort of live cold wet lives. They only run for a minute or so during a cold start. Hard not to have moisture in them. Mine sets false codes during cold, damp weather. Clear codes...warmer weather..false code problem goes away.

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Their is a TSB to correct this situation. The new pumps include the modification. Mine was just replaced on my 2001 DTS in order to pass Pa. Inspection

True. There is a TSB for a new hose design etc.

#02-06-04-024G: Service Engine Soon (SES)/Check Engine Light MIL Illuminated, Secondary Air Injection Reaction (AIR) Pump Ingesting Water, DTC P0410 Set (Replace Secondary Air Pump/Inlet Hose Assembly or Filter Kit) - (Jun 5, 2006)

My 2001 has the 'updated' hose kit. My version uses 1 blower. There are some versions that use 2. Maybe California certified uses 2 pumps...

That said, in a cool, moist enviroment. You will see moisture in the pump. You may even see a frozen pump with a blown fuse.

No heat from the engine, deep water prone, only runs a a minute or so at cold start up..plus.. when you are pumping cold, moist air. Guess what you get..water.

Warm, dry weather.. mine is ok.

I think I'm on my third pump...but almost 200k miles on the vehicle..

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Thanks for all the input guys. I changed both air pumps with the updated Delco TSB ones. Which have a protected inlet that snap into the inner fender walls to prevent taking in water. Still had a SES light on so I checked the fuses. I found one of the 50amp fuses blown. I imagine that happened when the air pump tried to kick on full of ice......result fuse blown. So after replacing the fuse I still had a SES. So I gotta say my man Ranger called it, he messaged me saying that it could be an electrical problem. At this point I was still dumb founded and couldn't figure out why my SES was still lite up. So I started removing the plastic top cover to inspect the vacuum lines. When I was undoing the four nuts that hold the cover on I could hear something shorting out as I pressed down on the cover. It turned out to be the main wire loom that runs across the top of the intake right above the rear valve cover. A little metal tab from one of the vacuum line brackets had cut through it and was grounding it out. Fixed the wire, taped it back up and once again cleared the PO412. I've driven 115 miles and still no SES. So I think I'm ready to pass Mass. state inspection. Two brand new Delco air pumps-$400, one 50amp buss fuse-$3.99, getting a total education in the secondary air injection system- "priceless" Thanks again for the feedback guys. And thanks again Ranger. -Caddy lover in Beantown.

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As info I had to drive my 2001 DTS after the new pump was installed about 100 miles to reset the computer before it would pass state inspection.

Depending upon the year and mileage the factory emission warranty may cover this repair????

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