Testing fuel gauge senders — AUDI

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Note:

Testing signal from fuel gauge sender:

=> Electrical system; Repair group 90
Electrical system

Special tools and workshop equipment required

V.A.G 1526 A

V.A.G 1594 A

Test sequence

Remove rear seat bench.

=> General body repairs, Interior; Repair group 72; Rear seats; Removing and installing rear seat bench
General body repairs, Interior
Rear seats
Removing and installing rear seat bench

Detach cover for flange on fuel tank under rear seat bench (right side).
Carefully release 4-pin connector -arrow- and unplug.

Connect multimeter (resistance test range) between contacts 2 and 3.

Fuel tank
Empty · Full
approx. 70 ω · approx. 270 ω

If the resistance is 0 ω,there is a short circuit. If the resistance is ∞ ω, there is an open circuit in the wiring.

Notes:

The fuel gauge senders -G, -G169 and -G237 are wired in series; for this reason, the three senders are tested together in this test.
To test one of the senders separately, remove the relevant sender => Page
20-229
.
In order to test the resistance for "tank full" and "tank empty" and move the float all the way to its top or bottom position after removing the relevant sender.
If you suspect a fault, you can check the resistance of the installed sender III (depending on level of tank) by pulling off the connection at sender II and measuring the resistance at the unplugged connector.

When the fuel gauge sender is removed, the arm of the float will travel further and the specifications are:

Vehicles built up to approx. 02.99

Sender removed from tank · Sender at bottom position · Sender at top position
Fuel gauge sender I / -G · approx. / 10 ω1) / · approx. / 70 ω
Fuel gauge sender II -G169 · approx. / 20 ω · approx. / 118.5 ω
Fuel gauge sender III -G237 · approx. / 30 ω · approx. / 81.5 ω

1)
The resistance is approx. 20 ωwith sender Iinstalled and fuel tank empty.

Note:

If one fuel gauge sender is defective on a vehicle built before about 02.99, all three sendersmust be replaced with senders of the newer version.

Vehicles of version from approx. 02.99

Note:

On vehicles built from about 02.99onwards the resistance ranges of senders II and III was changed, but the total resistance value => Page
20-218
remains the same.

Sender removed from tank · Sender at bottom position · Sender at top position
Fuel gauge sender I / -G · approx. / 10 ω1) · approx. / 70 ω
Fuel gauge sender II -G169 · approx. / 20 ω · approx. / 108.5 ω
Fuel gauge sender III -G237 · approx. / 30 ω · approx. / 91.5 ω

1)
The resistance is approx. 20 ωwith sender Iinstalled and fuel tank empty.