Removing and installing battery cut-off relay and battery isolation igniter — AUDI

🧭 Before you start

Disconnect the earth with the ignition off, remove the right luggage trim, foam inserts and cover, and unbolt the relay and igniter after discharging static. Refit in reverse with specified torques and locked connectors, and reconnect the battery with the ignition on and the car empty.

Fits: Audi A3 (8P, 2003–2012)

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• Follow pyrotechnic safety and disposal rules for N253.
• Discharge static by touching the door striker before unplugging or plugging the igniter.
• Make sure every connector is engaged and locked.
• Reconnect the battery with ignition on and no one in the vehicle.

Written for this job from the workshop steps below · TorqFix editorial.

📋 Procedure

1. ⚠ Observe safety regulations for pyrotechnic components .Observe disposal regulations for pyrotechnic components . — Switch off ignition and remove ignition key.
2. With ignition switched off, disconnect battery earth wire 27.
3. Remove luggage compartment side trim (right-side) .
4. Remove luggage compartment side trim (right-side) .
5. Remove foam insert from luggage compartment (rear right).

6. Remove foam insert from luggage compartment (front right).
7. Unfasten quick release fasteners (1) and remove cover (2).
8. Release latch on electrical connector and detach connector (3).
9. Unscrew nuts (4).
10. Unscrew nuts (5) and remove battery cut-off relay J655(7).
11. ⚠ Before handling pyrotechnic components (e.g. unplugging the electrical connector) the mechanic must discharge static electricity by briefly touching the door striker plate, or similar. — Release latch on electrical connector and detach connector (6).
12. Remove nuts (5) and take out battery isolation igniter N253(8).
13. ⚠ Observe safety regulations for pyrotechnic components .Before handling pyrotechnic components (e.g. plugging in the electrical connector) the mechanic must discharge static electricity by briefly touching the door striker plate, or similar. — Installation is carried out in the reverse order, note the following.
14. Observe the specified tightening torques .
15. When plugging in connector make sure it is properly engaged and locked in place.
16. ⚠ The battery must be connected with the ignition switched on. If pyrotechnic components (e.g. airbag or belt tensioner) are inexpertly repaired, this may result in unwanted triggering after connecting the battery. There must not be anyone in the vehicle while you are connecting the battery. — With ignition switched on, connect battery earth wire 27. [Note: If airbag warning lamp K75 indicates a fault following installation, you must interrogate, erase and then re-interrogate the fault memory .]

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