Control Module Function (Coding/Programming)
Control module function (coding/programming)Integrated functions
The vehicle electrical system control module includes the functions listed below:
- Monitoring of the vehicle electrical system status
- Monitoring of battery voltage and measures aimed at avoiding considerable voltage drops
- Detection of the vehicle electrical system status (critical/very critical)
- Introduction of measures aimed at improving the vehicle electrical system status and the removal of the critical/very critical vehicle electrical system status (load deactivation with terminal 15 on/off)
- Introduction of load management measures (idle speed increase and load deactivation)
- Measures at the start of a journey
- Measures for jump lead starting (emergency start)
- Measures in the event of a crash (accident)
- Information for the driver
Commissioning
When the ignition 'terminal 15' is switched on, an internal function test (initialisation phase) is performed in the vehicle electrical system control module. When the internal function test is completed successfully, all functions integrated into the vehicle electrical system control module are released.
Operating condition
The vehicle electrical system control module is in operating condition once the internal function test is completed successfully. Within the defined limits for the vehicle electrical system battery voltage '9.0 V to 15.0 V' and temperature, all incoming signals are processed by the integrated software and the appropriate monitoring and control processes are performed.
Permissible battery voltage:
- Ignition off/generator not running: 12.2 V: 'very critical vehicle electrical system status' is detected and load deactivation is initiated.
- Engine running/generator running: 12.7 V: 'critical vehicle electrical system status' is detected and idle speed increase is initiated. 12.2 V: 'very critical vehicle electrical system status' is detected and load deactivation is initiated.
Safety functions
- The headlights are switched on following a failure of the vehicle electrical system control module.
- Warnings are displayed in the instrument cluster.
- If a voltage of more than 17.7 V lasting for approx. 0.5 seconds is detected (e.g. jump lead starting), all loads that can be affected are switched off except for the internal light and the air-conditioning system. The idle speed increase is not functioning during this phase.
- If a voltage of less than 17.0 V is detected, the measures initiated previously are cancelled.
Switching off/on
Wake-up function via CAN data bus
Data transfer
The vehicle electrical system control module sends and receives data/information via the following 'CAN data bus':
- CAN comfort (B)
Diagnosis
Faults are only entered within the voltage range 9.0 V to 15.0 V. The specified voltage corresponds to the measured value on the measuring leads of the vehicle electrical system battery. In the event of an open circuit in the measuring leads, the vehicle electrical system control module receives an 'implausible signal', which is stored in the fault memory. Only the fault 'implausible signal' is stored in the fault memory; no other faults are stored. This approach is intended to speed up fault localisation. The exception to this approach is the 'Rain/light sensor' fault, which is also stored when the voltage is less than 9.0 V.
Fault memory
Faults that occur during operation are stored in a non-volatile memory (e.g. EEPROM). The faults remain in the memory even if terminal 15 and terminal 30 are not live. The fault memory is designed in such a way that the occurring faults, data source, fault type and error erase counter can be saved. The vehicle electrical system control module is powered directly from the vehicle electrical system battery and via terminal 30 for the interior light. The direct power supply and the power supply via the interior light are protected by two separate fuses. If the fuse for the direct power supply is faulty, a fault is stored in the fault memory. The vehicle electrical system control module is still powered via terminal 30 for the interior light and is fully functional. If the interior light fails, this fault is not stored in the fault memory because this is evident from the lack of lighting. The vehicle electrical system control module sends messages and checks the CAN comfort cyclically for messages from other control modules. If no messages are received for a certain time period, a fault is stored in the fault memory.
Coding
NOTE: If the coding does not agree with the vehicle equipment, faults will be displayed that do not really exist.
CAUTION:
Coding: make sure that the headlight system is coded correctly in the vehicle electrical system control module (always code Xenon headlights as well).
- Incorrect coding in the vehicle electrical system control module can damage the HBA Xenon control module.
Coding/Programming
Under the menu item "Extract coding" you can read out which equipment features are activated and which are not.
Modify coding
The following equipment features can be changed:
- Coming-home lighting
- Driving light (NAR) North America (change high beam headlight/ fog light activation with driving light on)
- Driving light assistant
- Comfort interior lighting
- Fuel pump (auxiliary heater)
- Cornering light
- Load management
- Fog lights
- Rear fog light
- Rear fog light (In Japan, the rear fog light is switched off in vehicles with level control when the highest position is reached.)
- Headlight washer
- Side marker lights/direction indicator lights (NAR North American Region)
- Seat heating
- Starter battery (2 battery power supply system)
- Daytime driving light
- Wake-Up level control (air springs)
- Xenon headlights