WARNING LAMPS

WARNING LAMPS
Turn signal indicators
When the turn signals are activated, the indicator lamp flashes.
If any turn signal indicator bulb is faulty or burned out, the indicator lamp flashes twice as fast.
This operating principle of the indicator lamp does not apply to turn signals of trailer devices.
Alternator
The indicator lamp lights up when the ignition is switched on.
It should go out after the engine starts.
If the indicator lamp lights up while driving, stop the vehicle immediately, switch off the engine, and check the condition of the generator V-belt.
If the belt is broken, you may continue driving without concern to the nearest service station. The engine coolant pump operates independently. At the same time, try to switch off all unnecessary electrical consumers, since battery charging has stopped and the battery may discharge. If the indicator lamp lights up and the V-belt is not damaged, seek assistance from specialists, as the battery charging process has been disrupted for some reason.
Trailer turn signal indicators *
The warning lamp starts flashing simultaneously with the activation of the trailer turn signals.
It stops flashing if any of the trailer turn signal lamps is faulty or burned out.
Engine Electronics *
The warning lamp comes on immediately after the ignition is switched on. As soon as the engine starts, it goes out.
If this does not happen, or if it comes on while driving, there is a malfunction in the engine electronic system.
The warning lamp also comes on when fuel of the wrong type or with a low octane rating has been added. It goes out when you reduce the engine load.
If the lamp does not go out or comes on again, drive at low speed to the nearest service station and contact specialists for assistance.
Glow Plug System (diesel only)
When starting a cold engine, the warning lamp comes on simultaneously with the ignition switch being turned on.
If the lamp does not come on, the glow plug system is faulty. Specialist assistance is required.
As soon as it goes out, start the engine immediately. If the engine starts while the warning lamp is on, the warning lamp does not come on during starting, and the engine may be started immediately.
ABS System *
The warning lamp comes on when the ignition is switched on. It goes out after the engine starts, when the generator warning lamp goes out and the self-diagnosis cycle is completed.
On vehicles with all-wheel drive, if the rear axle differential lock is engaged at this time, the lamp will only go out after the lock is disengaged.
If the warning lamp does not go out, or comes on while driving when the differential lock device is engaged but the lock has not yet engaged, try pressing the system activation button again.
If the lamp still does not go out, the ABS is faulty. In this case, the vehicle can only be braked through the conventional braking system. Contact a service station for assistance as soon as possible.
High beam
The warning lamp comes on when the high beam or the hazard warning lights and horn are activated.
Oil Pressure
On versions without the Auto-Check System, the lamp comes on immediately after the ignition is switched on. As soon as the engine starts, it goes out.
If this does not happen, or if it comes on while driving at a crankshaft speed of 2000 rpm and at the same time an unusual noise appears that is not typical of normal operation, stop the vehicle, switch off the engine, check the oil level, and top up if necessary.
If the lamp still does not go out after this, do not continue driving. The engine must not run, even at idle. Specialist assistance is required.
This lamp monitors oil pressure, not oil level. Versions with the Auto-Check System do not have this lamp.

Coolant Temperature / Level
The warning lamp flashes for several seconds after the ignition is switched on. This is the system function check mode.
If the lamp does not go out after the engine starts, or starts flashing while driving, this means one of two things:
the coolant temperature is too high; the coolant level is critically low.
In both cases, stop immediately, switch off the engine, and check the coolant level. Top up if necessary.
When the engine is hot, the coolant in the cooling system is under pressure. Therefore, before removing the expansion tank cap, wait for the engine to cool down. Do not touch the electric cooling fan! It may switch on at any time, even with the ignition switched off.
If the coolant level is normal, the fan fuse may have blown. Check and replace it if necessary.
If the lamp still does not go out in this case, do not continue driving. Specialist assistance is required.
If the presumed cause of the malfunction is the fan, the coolant level is normal, and the warning lamp has gone out, you may drive under your own power to the nearest service station. However, since airflow is required to cool the radiator, drive at a moderate speed and avoid running the engine at idle.
Test yourself
A quick Audi 80 quiz: every answer comes with an explanation and a link to the manual page.