ENGINE | 651.9 in MODEL 204.9 as of 6/1/12 |
View of engine from front left |
N3/9 | CDI control unit |
P07.16-3910-76
Task
The CDI control unit performs the following tasks:
Controlling the basic engine functions
Evaluation of input factors
The CDI control unit also acts as the interface (gateway) between the connected CAN bus systems.
Controlling the basic engine functions
- fuel supply
- glow system
- injected quantity control
– electronic accelerator
- diagnosis and fault storage
– thermal management
– exhaust gas recirculation
- exhaust gas cleaning
– torque coordination
– engine timing start/stop function
Evaluation of input factors
The input factors that have been read in are evaluated by the integrated microprocessor and the affected components are then actuated.
The electronic ignition lock control unit (N73) is the central interface (Gateway) for exchange of function-relevant data for control units which are connected to the various Control Area Network (CAN) bus systems.
Body
The housing of the CDI control unit is made of die-cast aluminum and the cover is made of corrosion-proof sheet steel. The CDI control unit is water proof and dust proof.
The housing contains the 32-bit measuring and control electronics for the engine control.
The CDI control unit has an internal atmospheric pressure sensor.
Voltage supply
The CDI control unit is supplied with power by "circuit 30 fused" and, with the ignition on, by "circuit 87". In the operating voltage range it has both short-circuit protection and reversed polarity protection. Power is supplied through several pins connected in parallel to relieve the electrical connectors.
Variants
The engine control variants (e.g. national and exhaust variants) are activated with Xentry Diagnostics using the variant coding function.
Assembly operations
Ensure before unplugging the plug on the CDI control unit that the ignition is switched off and processor run-on has ended. This is to prevent damage to the CDI control unit and save errors in the control units linked to the CAN.