Hi, I have MIL on with fault code 2003. This I believe is to do with the secondary air pump. Does anyone know where the pump and relay are located? Thanks

 

Thanks for your reply, I know there are more than just these parts but I want to know where they are so I can check these parts

 

Thanks for your reply. I know I have posted this in the wrong area but my VIN is WDD2193762A0451904. Hope you can still help.

 

thanks for your help. I now know where to start checking. The car often goes through some deep puddles and this may explain why it is an intermittent problem Thanks again

 

I have spent the last couple of days trying to solve this P2003 fault code and this is what I've done so far. Firstly I removed the tops from the two air shut off valves and removed the reed valves. It was a bit sooty in there from the exhaust but with the use of cleaning spray, a good wire brush and blow out with an air line soon had it cleaned up. With the tops removed I then pulled and maintained a vacuum on the diaphragm valves and made sure the diaphragms moved (simulating the opening to allow air into the exhaust) and reassembled. There is a small in line none return valve in the vacuum line to the changeover valve which I also removed, cleaned and operated satisfactorily. I ran a live and earth to the changeover valve and again simulated its operation and everything seemed ok. Disconnected hoses from head and once engine was cold performed a cold start. Still there was no air coming from the head to the air shut off valves. Removed relays from fuse box and bench tested satisfactorily and also checked fuse, all ok. Time to get under the car. On UK models the secondary air pump (smog pump)is behind the left hand fog lamp and you remove the panel under the radiator. Once panel removed I disconnected the smog pump and bench tested it. Success this time, the pump turned very slowly and the wiring got warm, suggesting it was still good but partially seized. It took me around an hour to strip the pump right down to the armature and brushes, and again everything was cleaned, blown out and the two bearings oiled. Reassembled and this time when it was bench tested it span up like a hair dryer, success I had found the cause and fixed it, hopefully, free of charge (UK stealer price is nearly £700). All put back together and fault codes cleared. Just waiting now to check it at next cold start to see if air is going to air shut off valves.

 

^^^ now that's digging in.

 

Well the next cold start came, no secondary air pump activity and engine management light came back on. Spent an evening looking at wiring docs and eventually discovered that on the CLS the K17 relay and fuse are in the boot along with the fuel pump relay. These are not on the rear SAM or prefuse unit but on a stand alone panel behind the boot trim on the right hand side. Accessed panel and found the 40 amp fuse had blown. Replaced fuse and performed a cold start. This time the secondary air injection pump spun into life, I have reset the code and hopeful this time it is fixed. This would of cost £1.000 from the main dealer. My price £1:20 plus lots of my own time

 

Awesome find. Did you determine what the cause was for the fuse blowing? 40 amps is quite a bit of pull to pop a fuse

 

Yeh, on U.K. Models the secondary air injection pump is located behind the front left fog light. Being low down it is quite prone to getting wet, and in a country where it always rains.......When I removed the pump and bench tested it it was turning very slowly and the wires were getting warm. Once stripped down the armature and stator were both quite rusty, hence the excess current draw. Once cleaned, bearings lubricated and reassembled it worked perfectly. There is not much info on the net about W219, so I thought I would post in this forum as it is basically an E class coupe, with many parts shared.

 

I'm having a similar issue and wanted to try to replace the relay and fuse but I can't seem to figure out where it's located, could you help a brotha out? Thanks in advance! WDDDJ76X36A010557

 

Secondary air pump code and fix. I recently repaired mine and replaced the air pump relay in the trunk. Simple DIY.