Secondary air injection pump wiring repair

[mnthny4]

Ok so u have a fault code for your secondary air injection system faulty ,and upon inspection u find wiring all peeling and shorted together ,dealer tells u it's 2k for repairs ,and u say I'm selling this %^#* right now ,don't sell just repair wiring it's just two wires negative and a positive ,positive comes from relay located under the engine ECM and negative is on the firewall behide or inline with oil filter housing section ,cost for repairs about less or more $150 in parts 12 feet 8guage wiring and from the dealer the pump connector and push pins ,a few butt connectors and a ring ground end to clamp on to neg cable end ,for the positive cable connection u will need to remove engine ECM cover pull ECM and put aside then below that is a fuse and relay block ,pull that up and look for the black relay that's plug into a purple colored connector ,be hide that find the solid RED thick wire that is the wire u want to butt connect the positive cable from pump to ,note u will need a roll or two of electrical tape and some tie straps cause your new wire harness will run along the original vehicle harness from secondary pump to relay box ,and the ground wire will go to the ground located on firewall just crimp ground ring on end of ground cable and fit to grounds location ,after all that clear code and run test to check pump function then recheck if code resets if it did not smile u just save $2000 plus for repairs ,cool .

[924Carrera]

Yep, except I actually removed the old wires and put the new ones inside the original harness. It really makes no sense to me why those wires and those wires only suffer that issue, when other wire of the same gauge and color in the harness is unscathed. The wire gauge is appropriate for the current the SAI pump uses, and the 60A fuse should blow before the wiring melts. It looks more like it suffered heat from the outside, which would be plausible in that engine bay, but the other wiring is totally fine...

[mnthny4]

One of the reason that the wiring coating melts or just cracks up may be due to the pump at times been a bit tight to operate due to a bit of water in the pump housing at times causing the pump to work harder generating more heat on the wiring over a period of time ,just my 2cents not really sure .

[924Carrera]

One of the reason that the wiring coating melts or just cracks up may be due to the pump at times been a bit tight to operate due to a bit of water in the pump housing at times causing the pump to work harder generating more heat on the wiring over a period of time ,just my 2cents not really sure .

Well, I too was thinking the pump might be overworking at times, but the issue I have with that theory is that the wiring is rated beyond what the circuit is. That fuse should blow if the pump starts drawing more than 60A, and the wiring should hold up to around 65 or 70 without damage (based on the gauge). In the case of my car, the fuse was miraculously not blown despite the nearly bare wires side by side. Also, that pump only runs for a short time on cold starts to speed up the catalyst warmup, so it's not like it has a huge duty cycle.

[mnthny4]

Well it's a good thing we know how to fix this Audi nightmere ,it's only the audi's I see with this issue mostly ,so we save from buying a complete harness with this fix ,cool.

[GRCYGTR]

This thread is 2 years old but is very applicable to my situation right now and I am hoping I can get some clarification.

When you "butt connect" to the red wire from the relay to the new pos wire, does that mean you remove the wire from the relay housing? Or do you splice it in so that now both your new positive cable from the pump and the original red wire are both connected to the relay? I think you would need to keep the original in the relay, otherwise you wouldn't be able to complete the circuit.


Thanks in advance,
Peter