Bulb failure indicator light, function - GF54.15-P-1520CS
MODEL 129
The exterior lamp failure monitoring module N7 in the fuse and relay box F1 monitors the function of the bulbs in the following circuits for exterior lighting:
- Side light
- Low beam headlamp
- High beam headlamp
- Fog lamp
- Tail lamp
- Registration plate lamp
- Stop lamps.
- Turn signal lamp (model 129 until 31.08.95)
- Rear fog guard light
- Backup lamp
If a bulb or fuse fails in the low beam headlamp, side lights or tail lamp circuit, this is indicated by the exterior lamp failure indicator lamp A1e14 in the instrument cluster only when the exterior lighting is turned on. If the corresponding circuit is switched off, the indicator lamp extinguishes.
If a bulb fails in the stop lamp or turn signal lamp circuit (model 129 up to 31.08.95), this is stored by the lamp monitoring unit and indicated for as long as the ignition/start switch (S2/1) is in position 2.
To determine which bulb is faulty, start the engine then switch on both left and right turn signals and apply the brakes. Then turn on the side lights and all other lights one after another until the indicator lamp comes on.
If several bulbs are controlled for one function, after the indicator lamp comes on, the faulty bulb must be determined by means of a visual check.
The exterior failure indicator lamp (A1e14) lights up dimly as a self-test from position 2 of the ignition/start switch and extinguishes immediately once the engine is running.
If additional lights are retrofitted, for example auxiliary headlamps, auxiliary stop lamps, a trailer towing device, etc. it must be ensured that these are connected to the fuse upstream from the exterior lamp failure monitoring module N7. Other types of connection may lead to incorrect lamp failure indication and cause damage to the lamp monitoring unit.