The check-control is an active information system which informs the driver via the text display in the instrument cluster of the failure of important functions as well as providing other information and warnings. These text messages are in part accompanied by and acoustic signal (gong).
Corresponding to the effect on driving safety and reliability, these messages are allocated to various priority groups and displayed accordingly.
If there are still further messages concerning the message currently displayed, they are indicated by the note symbol being permanently switched on.These messages can be called up by pressing the check-control button.
The message language can be coded.
Testing and diagnosis take place via the I-bus.
The check-control module receives its information for messages
The CC button is located on the right-hand side in the instrument cluster and is evaluated in the instrument cluster electronics (IKE).The check-control module is informed via the I-bus when the CC button is pressed
If no CC messages are awaiting to be displayed when the CC button is pressed, "CHECK CONTROL OK" is displayed when the button is depressed. The display goes out again when the CC button is released.
If there is more than one check-control message pending they can be called up one after the other with the aid of the CC button.
The gong in conjunction with CC messages is activated via the I-bus (no direct line link between CCM and gong!).It should be noted that - depending on the importance and number of previous messages - an acoustic signal does not sound every time, also not for the same message.
The oil level is determined by the thermal oil level sensor.
The thermal oil level sensor is connected via a line link to the check-control module and supplies a square-wave signal whose frequency represents a measure for the oil level.
It is supplied with voltage as of terminal 15.
The brake fluid level switch is connected to the CCM via a signal-wire link.
The check-control module is connected to the wash water level switch via a signal-wire link.The message is output with a delay of 25 s due to the sloshing movement of the fluid level.
The check-control module is connected to the coolant level switch via a single-wire link.The message is output with a delay of 25 s due to the sloshing movement of the fluid level.To provide a quick indication when starting off, the message is output without delay at "terminal 15 ON".
The check-control module is connected via a line link to the DDE control unit, from which it receives the signal for the messages "preheating" and "fuel injection system".
If problems are detected at the throttle or at the pedal position sensor, the EML assumes an emergency program with a distinct reduction in engine output power.In this case, the CCM receives a signal via a line link from the EML and outputs the message "emergency engine program".
Appears if the CCM is not coded.
A switch is located in the ignition lock which is connected to the check-control module via a single-wire link and switches with respect to ground.
The display appears when the driver's door is opened until the ignition key is removed, but only as of "Terminal 15 OFF".
In US and Gulf State vehicles, the message appears as of "Ignition ON" if the belt has not been buckled.The belt contact switch which switches with respect to ground is connected directly to the check-control module.
The check-control module receives information from the IKE for the following messages. In the case of incorrect messages, troubleshooting should be continued in the instrument cluster electronics (IKE).
Emergency transmission program (automatic only)
If there is a defect in a transmission control unit connected to the IKE, the check-control module is informed of this status via the I-bus and the message displayed.
Release parking brake
To draw attention to the applied parking brake when starting off, this message is displayed as of a speed of 5 km/h.The gong only sounds when the message appears for the first time.
Check brake pads
The IKE informs the check-control module with regard to wear of the brake pads.
Coolant temperature
This message is displayed if the maximum permissible coolant temperature is exceeded.To avoid incorrect displays, monitoring takes place 10 s after the minimum speed has been exceeded.
Stop!Engine oil pressure!
A drop in the oil pressure below the permissible limit is signalled to the driver.Evaluation of the sensor begins 10 s after the minimum engine speed has been exceeded.
The check-control module receives information from the ZKE and processes it for following messages.In the case of incorrect messages, troubleshooting should be continued in the ZKE.
Door open
This message is displayed as of 5 km/h if the driver's door, passenger's door or a rear door is open.
Luggage compartment open
To draw attention to an open luggage compartment lid when driving away, this message is displayed when a speed of 5 km/h is exceeded for the first time.
Lights ON?
The display appears in ignition lock position "0" if the driver's door is opened with the parking lights switched on.
Following messages are preprocessed by the light module and transferred to the check-control module by way of telegram. In the case of incorrect messages, troubleshooting should be continued in the light module.
Check brake light
Check high beam
Check low beam
Check parking light
Check tail lights
Check front fog light
Check rear fog light
Check licence plate light
Check reversing light
Check trailer light
Lights ON?
The display appears in ignition lock position "0" if the driver's door is opened with the parking light switched on.