Checking fuel pump relay: Audi 1.8 (ADR, AFY)
Step-by-step checking fuel pump relay for the Audi 1.8 (ADR/AFY): 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
AFY
Voltage is supplied to the fuel pump and some injection system components via the fuel pump relay (J17).
The condition for the closing of the fuel pump relay (J17) is that the engine should be turning. i.e. the relay is only connected to earth (via the engine control unit) when engine speed pulses are detected in the engine control unit.
Test conditions
Battery voltage OK.
Functional testing of fuel pump relay
Start actuator diagnosis and activate an injector => Page
01-44
.
The fuel pump relay (central electrics, relay position 6) must pick up ...
If the relay does not pick up, test activation of fuel pump relay =>Page
24-30
... and the fuel pump must run.
If the fuel pump does not run, check activation for fuel pump and components
=>Page
24-32
Checking actuation of fuel pump relay
Switch off ignition.
Connect test box V.A.G 1598/22 to wiring harness for engine control unit
=> Page
24-6
.
Connect together sockets 4 and 2 on the test box using an auxiliary cable from V.A.G 1594.
Switch the ignition on.
Specification: The fuel pump relay (central electrics, relay position 6) must pick up ...
If the relay pulls now, but not during final control diagnosis:
Renew engine control unit
If the relay does not pull:
Switch off ignition.
Remove fuel pump relay from relay base (central electrics, relay position 6).
Connect the multimeter to contact 2 of relay socket and earth to measure voltage.
Switch the ignition on.
Specification: approx. battery voltage
If the specification is not obtained:
Check the wiring.
=> "Current Flow Diagrams, Electrical Fault Finding and Fitting Locations" binder
If the specification is obtained:
Switch off ignition.
The following wiring connections should be checked for open circuits and/or short to positive or negative.
Central electrics, relay base 6, contact · Test box V.A.G 1598/22, socket
29 · 4
Rectify any open/short circuit as necessary.
If no wiring fault is detected:
Renew the fuel pump relay (J17).
Checking actuation of fuel pump and components
Withdraw the fuses 28, 29 and 34.
Start actuator diagnosis and activate an injector => Page
01-44
.
Connect the multimeter for voltage measurement to the left-hand and right-hand contacts of the following fuses:
Fuse No. · Specified value at left or right contact
28 · approx. battery voltage
29 · approx. battery voltage
34 · approx. battery voltage
If the specification is not obtained:
Check the wiring.
=> "Current Flow Diagrams, Electrical Fault Finding and Fitting Locations" binder
If no wiring fault is detected:
Renew the fuel pump relay (J17).
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
- Checking intake air temperature sender
- Draining – VW Sharan I / SEAT Alhambra
- Removing toothed belt, vehicles with old toothed belt tensioner
- Connecting fault reader V.A.G 1551 and selecting functions
- Checking system pressure, fuel pressure regulator and holding pressure
- Removing and installing toothed belt – Audi · 56 torque figures
- Removing engine – Audi A8 D3 · 41 torque figures
- Removing camshaft timing chain from camshafts – Audi A6/A7 C7 · 38 torque figures
- Installing engine – Audi A8 D4 · 36 torque figures
- Removing and installing camshaft timing chain · 29 torque figures
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.