Fuel Pump Relay, Checking Audi A8 D3 facelift

Fuel Pump Relay, Checking

Note. Fuel Pump (FP) relay is located in relay- and fuse holder, relay position 4 in front right footwell.

1. Remove Fuel Pump (FP) Relay J17 from relay position 4.
2. Switch ignition on.
3. Connect portable multimeter VAG1526 in sequence between terminals 3 (B+, terminal 15) and 2 (Ground GND) as well as 1 (B+, terminal 30) and 2 (Ground (GND)) of relay socket.

Specified value: approx. battery voltage respectively.

1. If no battery voltage is displayed, measure plus terminals to vehicle Ground (GND) as a test.
2. If there is still no battery voltage, check plus wires (terminal 15/terminal 30) for open circuit. --> Electrical Wiring Diagrams, Troubleshooting and Component Locations
3. If battery voltage is displayed when measuring to vehicle GND and not at terminal 2, check wire connection from terminal 2 via fuse (in relay- and fuse holder in instrument panel, right side) to Transfer Fuel Pump (FP) G23. --> Electrical Wiring Diagrams, Troubleshooting and Component Locations

1. Connect voltage test lamp VAG1527 between terminal 3 (B+, terminal 15) and 4 (Ground (GND) activation of Engine Control Module (ECM)).
2. When switching on ignition, voltage test lamp must light up for approx. 1 second and then go out. When operating starter, voltage test lamp must light up constantly.

Note. Voltage test lamps with low current draw do not go out completely after 1 second, but rather light up weakly until starter is operated.

If voltage test lamp now lights up, replace Fuel Pump (FP) Relay J17.

If voltage test lamp does not light up, check wire as follows

1. Connect test box VAG1598/31 to wiring harness of Engine Control Module (ECM) --> «Wire and Component Test at Engine Control Module using VAG 1598/31»(ref-289208-S32498292062008062700000) .
2. Connect portable multimeter VAG1526 between terminal 4 of relay socket and socket 65 of test box and check wire connection for continuity.
3. If specified value is not obtained, check wire connection for open circuit or short circuit. --> Electrical Wiring Diagrams, Troubleshooting and Component Locations
4. If there is no open circuit and voltage test lamp does not light up, replace Engine Control Module (ECM) --> «Engine Control Module, Replacing»(ref-289208-S06773057402008062700000) and generate readiness code again --> «Readiness Code, Generating»(ref-289208-S31500925522008062700000) .

1. Read readiness code --> «Readiness Code, Reading»(ref-289208-S39034557822008062700000) . If DTC memory was erased, readiness code must be generated again --> «Readiness Code, Generating»(ref-289208-S31500925522008062700000)