EA / CC / ISC control module position / task / design / function

P30.20-2008-01

N4/1 EA/CC/ISC control module

Purpose

Controlling the position of the throttle valve in line with the input signals.

Design

 voltage supply

 set value selection

 pedal maps

 ASR/EBR signal processing

 limiting starting-off torque (only engine 120)

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 limiting load value (only engine 120)

 limiting maximum vehicle speed (only engine 120)

 vehicle speed selection

 position controller

 output stage

 emergency running

 cruise control/idle speed

 fault memory

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Function

Voltage supply

With ignition ON, voltage is supplied by the EA module to the following components:

 set value and actual value potentiometer

 actuator motor

 clutch

 cruise control switch

 idle speed contact switch

 safety contacts

In addition on engine 120 for the left actuator, positioned on right of engine:

 actual value potentiometer 2

 actual value potentiometer 3

 clutch

 direct-current motor

Set value selection

The following signals are input:

 idle speed input

 accelerator pedal input

 ASR/EBR input

 maximum vehicle speed input

 Cruise control input

The signal with the highest priority is determined.

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Pedal maps

The appropriate map is actuated in line with

 accelerator pedal position

 selector lever position (reverse)

 engine speed

ASR/EBR signal processing

The ASR/EBR data are transmitted by the ASR control module through the CAN data bus to the EA control module. Priority is given to the signal with the highest priority and this controls the throttle valve. If no ASR/EBR signal is received, the accelerator pedal position determines the throttle valve position.

Limiting starting-off torque (only engine 120)

The EA control module controls the engine output torque to a particular limit torque below a vehicle speed threshold of 5 km/h, in line with selector lever position D, 3, 2 or R, in order to protect the drive train. This is done by limiting the opening of the throttle valve irrespective of the position of the accelerator pedal.

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Limiting load value (only engine 120)

The EA control module is supplied with a load value limit signal by the ignition control module through the data bus. The signal is active if, for example, the fault, knock sensor defective, or camshaft sensor implausible, is detected in the ignition control module. This results in the ignition being retarded and, in this case, the EA permits only a particular opening angle of the throttle valve.

Limiting maximum vehicle speed (only engine 120)

Maximum vehicle speed is limited to 250 km/h. If this speed is exceeded, the throttle valve is closed irrespective of the position of the accelerator pedal.

Position controller

Compares the throttle valve position and accelerator pedal position. The position controller corrects the position in line with the set and actual value.

Output stage

Operates the positioning motor in the actuator.

Emergency running

In the emergency running mode, the output stage for the clutch and for the positioning motor is switched off. The throttle valve can then only be operated mechanically through the accelerator pedal.

Fault memory

All system components are monitored by means of a watchdog in the EA control module. Faults are stored in the fault memory of the control module and are retained even if the battery is disconnected.