Symptom Related Diagnostic Procedures

Voltage Supply For CID, Central Information Display


CID supply lines:
The Central Information Display (CID) is the indicating instrument of the headunit; it does not generate its own screen contents. The CID is switched on and off using the headunit and is supplied via the following connections:
- Ground connection
- Terminal 30g
- K-CAN connection (logical control)
- LVDS data line (picture signals from the headunit)

CID screen failure:
The CID is not faulty when the picture and audio playback fail at the same time. In this case, the function of the headunit must be checked first. The same applies to delayed switch-on, frozen graphics or partially hidden image contents. When audio playback is present, check the function of the CID and head unit (see also Chapter "Red Screen").

Faults with regard to LVDS signal:
If there is a fault entry with regard to the LVDS signal, the operability of the headunit must be checked first followed by the LVDS data line (see also Chapter "red screen").

Faults with regard to excess temperature
The temperature of the CID can rise considerably under unfavorable operating conditions.
In this case, the CID lowers its brightness. In extreme cases, the CID can even completely switch off. If it is switched off, a fault entry is placed in the CID.

Possible reasons for excessively high temperatures in the CID:
- High ambient temperature
- Strong sunlight
- Strong heat from the heating duct

Faults with regard to brightness
The brightness of the CID is controlled depending on various signals. Brightness of the CID to which the customer is not accustomed can lead to complaints. In this case, take account of the following causes:
- An individual brightness value can be set for the CID. The brightness value is set at the controller via menu guidance. The set brightness value depends on the ignition key.
- Under certain circumstances, the set brightness value can be reset after programming or after undervoltage.
- At very high temperatures in the CID, it reduces the brightness.
- The brightness of the CID is controlled depending on the signal terminal 58g as soon as the light is switched on.
- The brightness of the CID is controlled depending on the light intensity registered by the instrument panel or built-in photosensor in the CID (if installed). The function of the sensor can be checked with a torch.

Pixel faults
Pixel faults are not a reason for replacement.

Red screen ("No Signal Screen")
With LVDS data faults, the CID will display a red screen for about 30 seconds ( No Signal Screen). The CID will then switch off completely and remains deactivated as long as the LVD data fault is present. This is not a malfunction of the CID. In this case, the operability of the head unit and LVDS data line must be ensured.

E89 CID folding mechanism, manual adjustment:
A manual adjustment of the position of the E89 CID folding mechanism by hand is not available and may lead to malfunctions and fault entries.