Main Relay

Post by **JayRyan** » Jun Mon 23, 2008 9:06 am

Well, instead of driving, I ended up wrenching. It started with a friend who's Passat was throwing a misfire code. The car just rolled over 100K and the CPs and plugs were originals so she ordered new ones.

Well...

We got her CPs and Plugs changed out before which her dad moved it into the garage on 3 cyl (new CPs and plugs) after breaking the connection on the fourth to try and fix it in the garage

Anyway, got it fixed and all changed out but now it's throwing a P1517 Main Relay Cir Electrical Malfunction Code and won't start.

Thoughts? Before I have her just order a new switch? Mike, is there a way to test it?

Gotta love VWs

YouTube · Post by **Mikewire** » Jun Mon 23, 2008 9:55 am

Wow, thats the ECM relay. I would suspect it's something simple like a ground or a + cable either loose, not connected or broken. I may be able to get your more info if you can give me a year/engine type or engine code.

Post by **JayRyan** » Jun Mon 23, 2008 10:14 am

MikeWire wrote:Wow, thats the ECM relay. I would suspect it's something simple like a ground or a + cable either loose, not connected or broken. I may be able to get your more info if you can give me a year/engine type or engine code.

I couldn't find anything. I had to rig the connection for the CP on cyl 2. Not sure that may have caused it....

'00 1.8TM
ATW

All I've been able to come up with is "replace it"

YouTube · Post by **Mikewire** » Jun Mon 23, 2008 12:09 pm

You could test for ~12V at the relay - pull it and check the sockets with your MM - that's the procedure in the repair manual. IMHO if it's cheap and available I would replace it just because. I'm not sure how to test a relay - you could rig a 12V, ground and a switched source on a test bench and if it clicks over then it should work. That's relay #428 right? Could you swap yours out to see if it fixes the problem?

Post by **JayRyan** » Jun Mon 23, 2008 12:58 pm

MikeWire wrote:You could test for ~12V at the relay - pull it and check the sockets with your MM - that's the procedure in the repair manual. IMHO if it's cheap and available I would replace it just because. I'm not sure how to test a relay - you could rig a 12V, ground and a switched source on a test bench and if it clicks over then it should work. That's relay #428 right? Could you swap yours out to see if it fixes the problem?

Well...I'm hesitant to swap out because a) my ECU cover's a b&^$## to get off and I'm wondering if my rigging of the busted casing on the CP for cyl. 2 caused it $:\$ I might just have her buy a new one, I think they're only around $12. I"m not sure which it is though. There's three of them in there. I don't own a Bentley neither.