1 Fault Found:

17925 - Power Supply Relay for ECU
P1517 - 35-00 - Electrical Malfunction

Readiness: 0110 1101

So, have an issue with the above code on my 2002 New Beetle 1.8T. After some research, this code seems to be quite prevalent on various 1.8t's - particularly older models. I removed the J271 ECU power supply relay # 428, which is located in a relay box behind the battery.

Checked to ensure there was no water damage etc. After some testing of this ECU relay I concluded that it was faulty - the resistance between pins 85 + 86 was exhibiting very high - around 152 ohms, although the relay did appear to operate ok. Not chancing it, I purchased a brand new ECU relay from my local VW dealership [part # 1J0906381B] and this was showing around 75 ohms between the pins [which it should be typically].

I installed this new ECU Relay, did a capacity discharge, cleared the error code and did a TBA to boot.

The 1.8t fired straight up - no issue, no rough idle and no fault codes.

Next day, went to start it... cranks but no start.

The above code has returned

*Battery is fully charged, bought new 2 months ago.. also has a brand new Camshaft hall sender [part # 058905161b] installed last month [was previously giving error code 17746]

I also removed the ECU last month and checked all connections / connectors and cleaned them with IPA.

Now then.

At this point - I know 100% that it is the wiring loom to the ECU relay that is at fault.

I have a DVM to hand, but would really appreciate if someone could give me a little guidance on the wiring etc and where to test at the relay block - as it's really cold outside and don't want to stand out there any longer than necessary!