Code p0410 Secondary Air Injection?
 

My 2000 ML430 had the CEL light come on and threw code p0410 (Secondary Air Injection). Also the Secondary Air Injection 40 amp fuse was blown. I just had the brake fluid replaced, not that it's related but I wonder if a part of the engine was damaged while replacing it. The vehicle seems to run good, despite the CEL. Any suggestions?

Since air injection is an EMISSION warm-up system you shouldn't notice any runing problem.... Replace fuse/erase code & wait till tomorrow & see if the pump runs then.

CEL is back. Fuse is not blown this time and scan indicates code 410 again. Any ideas?

There are at least 5 possibilities!

The air pump MUST run.
The air pump diverter switch-over valve must receive signal & open.
The air injection diverter valves must get vacuum from the switch-over valve.
The diverter valves must open allowing air into the exhaust.
The front oxygen sensors must se that oxygen & react by dropping their output to almost no signal.

Scanners that have a activation feature can perform those needed tests!

Determined to resolve this issue I decided to check the fuses and found the following:

-Fuse F14 (25A), which is listed as (Diesel) Injection System had a 15A fuse in same and was blown. I replaced with the proper 25A fuse, although I don't know if this fuse is functional, as the ML430 is not a diesel.

-Fuse F40 (20A), which is listed as the Vacuum Pump was missing, which I replaced.

-Fuse F44 (30A), which is listed as Air Conditioner Blower had a 30A fuse in same and was blown. I replaced with the proper 30A fuse, however with the winter months, I have not been using and the air which worked fine over the summer.

I'm sure in some way these findings contributed to the CEL and code p0410, but am looking for some definitive feedback. I never had CEL issues before and never checked all the fuses. Also will the CEL reset itself, provided the new fuses resolve the problem, or do I need to reset it through the scanner? Anyone?

Do you now hear the AIR PUMP run in the morning??? hood open & engine COLD...

I believe I do hear it, but I can't confirm for sure it didn't come on before. My concern about erasing the 410 code is that I had the vehicle scheduled to go in for the problem, prior to discovering the blown and missing fuses, and the mechanic may have nothing to go on.. Now that I have replaced and repaired, I feel it may be a waste of time and money to have the vehicle serviced.

With a scanner designed for MERCEDES a technician can activate that system & see if it functions correctly..

That is the BEST way to determine the problem.

For those who were following the post, I needed a new air pump.

I had the CEL and a P0410 code on my '97 E320. Air Pump is working, no blown fuses. I was told it could be caused by a blocked valve due to buying lower quality fuel (93 Octane but at a low cost gas station).

I was told the repair is to remove the head clean the valve. Instead I bought some Techron fuel additive, cleared the code (for the second time), added the Techron and voila, the code has not returned for 2 weeks. I've only used Shell fuel since the code came on the first time.

Not sure if I really solved anything, what do you guys think?