fastneutron

My C43/55 has been running great for a year since the engine swap, but recently I've been getting CEL with code P0410. I would like to replace the relay first because the motor still has continuity. So I'm hoping it's just the relay not actuating. Can anyone tell which is the secondary air injector relay on the attached picture? Is it the multi-purpose relay with part number A0025421319?

Thanks in advance.

Tony_AMG

I am also interested if the relay can cause a P0410 on C43/C230k and where is the right location to find them.

RPB

For about a year my 95' C36 had the P0400 & 0411 code. I started by replacing my pump which had gone bad and was soaked in water when I removed it. The fuse kept blowing too which is typical when the pump goes out. Two weeks later my replacement pump stopped again and was drenched. Come to find out my EGR shut-off valve was bad and leaking stuff in the air pump. So after replacing both of these components I was still getting a P0400 code. The last thing I replaced was my relay which is pink not like yours, and have so far gone 110 miles without any CEL. I was told that MB used to always replace the relays along with the pump, so I did. I'm almost positive now that a bad replay can cause these codes. Best of luck, it's not too expensive around $20-30 and is a good place to start! Sorry I am not sure which relay it is on your model though, but I am pretty sure that is the correct part # you have. It's definitely a multi purpose relay on my car.

Inteldrour

A P0410 could be a bad air pump or pump relay. P0410 is an electrical issue with the air pump, located under the drivers side headlight behind the bumper.