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아우디 A3 수리 사례

8Y (2020-현재) · 35 TFSI 자동

2026. 11. 7. 작업

난이도 & 준비물

증상

Great thread.

처리 내용

macron said: And I thought these were simple cars! Great read OP!they are compared to more modern things but throw in age of components and a fault which is hiding in plain sight and it becomes a mission to solve it... I've literally tested every possible thing, even went as far as thinking there's an issue with the fuel return line being blocked. This version of A3 has a curious fuel filter in that the fuel pressure regulator is built into the filter, the fuel feed goes forward to the fuel rail via a single line, with no return from the rail back to the tank. The return line is off the fuel filter and is regulated by the in tank pump. So to eliminate that you remove the return off the filter and decant into a receptacle. Proved absolutely nothing lol, other than a running car at idle fills a 5 litre fuel can very quickly... The only thing i found was when comparing the 2 ecu's... is it a red flag or the actual issue? i genuinely don't know until ive eliminated the loom. So i bench tested the pair of them, the ecu was powered with a reliable, fused 12.7v powerbrick and i measured everything resistively and volts. Live operational parameters on Engine data (this is all on VCDS) Block 033 showed field 2 (Lambda Sensor Voltage) locked completely out of specification at 0.98V, signalling an extreme rich condition to the microprocessor. In response, field 1 (Short-Term Fuel Trim) maxed out negative corrections at a constant -27.7%, while injector timing was compressed down to a baseline limit of 2.03 ms. Bench analysis isolated a possible internal hardware fault within the original ECU's peripheral circuitry: specifically, an internal component drift/leakage on the 5V reference rail track causing a 0.52k Ohm deviation to chassis ground.if this doesn't cure it all i'm using the over fuelling fault as a means to ignite the damn thing....!!!