General Information

WARNING: This page is about a different car, the 2016 Audi A8 Quattro and 2015 Audi A8 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

Fuel Supply/Injection

The engine control module is equipped with On Board Diagnostics (OBD). Before repairs such as fault finding, check the Diagnostic Trouble Code (DTC) memory first. Also the vacuum hoses and connections must be checked (unmetered air).
For the electric components to work properly, a voltage of at least 11.5 Volts is required.
Do not use sealants containing silicone. Particles of silicone drawn into the engine, will not be burnt in the engine and damage the oxygen sensor.
The vehicles have a crash fuel shut-off. It reduces the risk of fire in an accident because the fuel pump is switched off.
This setup also makes it easier to start the engine. When the driver-side door is opened, the fuel pump is activated for 2 seconds so that pressure builds in the fuel system, observe safety measures. Refer to FUEL SYSTEM SAFETY PRECAUTIONS .

Glow Plug System

The pre-glow system is controlled by the Automatic Glow Time Control Module -J179-. The control module has On Board Diagnostic (OBD) capable systems.
Automatic Glow Time Control Module -J179- component location. Refer to Wiring Diagram.
If there is a malfunction in the preglow system, a fault will be stored in the Engine Control Module -J623-.
Checking the preglow system is explained in "Guided Fault Finding".
Electronically controlled glow plugs with a separate glow plug control module were installed in order to reach a quick starting function.
Each glow plug is controlled and diagnosed individually.

NOTE:

Wait 60 seconds after each glow plug control module output diagnostic test. The ignition must remain switched on.

If the 60 second waiting period is not observed, (if the ignition switched off and then back on again), the glow plugs could be damaged (by a repeated preglow).

The glow plug control depends on the coolant temperature.