Testing Motronic current supply relay -J271: Audi 1.8 (APT, AQE, ARG, ARH, …)
Step-by-step testing Motronic current supply relay -J271 for the Audi 1.8: factory workshop text. What to remove, in what order, and what to check after.
Workshop procedure for AUDI — the factory write-up, straight from real workshop data.
📋 Procedure
ARG AVV
Fitting location of current supply relay: relay position 3 in electronics box in plenum chamber.
Test activation of current supply relay
Switch off ignition.
Remove cover of electronics box in plenum chamber.
Pull current supply relay out of relay carrier.
Connect test box 1598/31 to wiring harness of engine control unit. Do not connect engine control unit itself => Page
24-10
.
Test for open circuit or short circuit in the following wiring connections.
Test box V.A.G 1598/31, socket · Current supply relay, Contact
21 · 4 / => Current flow diagrams, Electrical fault finding and Fitting locations
Wiring resistance: not more than 1.5 Ohm
Rectify any open circuit or short circuit as necessary.
=> Current flow diagrams, Electrical fault finding and Fitting locations
If wiring is OK:
Test voltage supply of current supply relay.
Testing voltage supply
Switch off ignition.
Connect hand-held multimeter (voltage measurement range) between earth and contacts 2 and 9 of relay socket.
Specification: approx. battery voltage
If the specification is not attained, check voltage supply according to current flow diagram.
=> Current flow diagrams, Electrical fault finding and Fitting locations
If the specification is attained, test wiring connection between current supply relay and engine control unit.
Testing wiring connection between current supply relay and engine control unit
Test fuse 29 (see current flow diagram).
=> Current flow diagrams, Electrical fault finding and Fitting locations
If fuse is OK:
Test for open circuit or short circuit in the following wiring connections.
Test box V.A.G 1598/31, socket · Current supply relay, Contact
121 · 6 / => Current flow diagrams, Electrical fault finding and Fitting locations
Wiring resistance: not more than 1.5 Ohm
Rectify any open circuit/short circuit as necessary.
=> Current flow diagrams, Electrical fault finding and Fitting locations
If no fault has been found during any of the tests, renew current supply relay -J271.
TorqFix answers live for your specific car — tell it the engine code and it serves the matching sequence, torque figures and wiring for that exact variant.
Ask about my car →Other AUDI procedures
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Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.