wiring AUDI S4 1998 B5 / 1.G Engine Manual

11
Fan control
The control unit for radiator fan V293 regulates
the output of the radiator fan and controls the
continued coolant circulation. The induced-air
fan V7 and the forced-air fan V177 are
activated simultaneously.
Forced-air fan V177 is located upstream of the
condenser, water cooler and visco fan. It
assists the visco fan.
The electronic power control
The various fan settings are executed by an
electronic power control.
The fan motors are operated periodically, the
length of the operating cycle depending on the
fan setting selected. Fan output level is
controlled via pulse-width-modulated outputs.
Should a fan fail, the radiator fan control unit
increases the speed of the fan motor still
available.
Advantages of the power control:
•
The series resistors previously used for
power control are no longer required.
•
Lower power consumption in lower fan
settings.
•
Safety functions.
The power supply is protected by a
fuse on the 8-socket relay plate. For
the correct fuse rating, please refer
to wiring diagram.
Vehicles equipped with an air
conditioner require a higher fuse
rating than vehicles without an air
conditioner.
SSP 198/50

8-socket relay plate
SSP 198/55

Control unit for radiator fan
attached to front right
vehicle side member
Fuse, terminal 30
Fuse, terminal 61

39
Self-diagnosis/emergency
running
If a fault occurs in the accelerator position
sender or the wiring, two emergency running
programs can be run depending on fault type.
Emergency running program 1
If an accelerator position sender fails:
• Accelerator position limited to a defined value.
• If a full load is predefined, the power output is
increased slowly.
• In the case of implausible signals between G79
and G185, the lower value is used.
Prerequisite:
The idling speed position must be learnt once
by the intact sender.
• The signal supplied by brake light switch for
brake pedal switch F47 indicates the idling
speed.
• Comfort functions (CCS) are prohibited.
• The fault lamp for electric throttle control K132
comes on.
Emergency running program 2
If both accelerator position senders fail, driver
input recognition is not possible:
• The engine only runs at idling speed.
• The fault lamp for electric throttle control K132
comes on.
At idling speed, the accelerator
position senders G79 and G185 are
not diagnosed.
If the plug of the accelerator position
sender drops off, no fault is stored in
the control unit.
The fault lamp for electric throttle
control K132 does not come on.
The engine runs at idling speed and
does not respond to the accelerator
pedal.
Safety function:
For safety reasons, the throttle valve
is closed as far as a defined angular
position when both the accelerator
pedal and the brake pedal are
depressed.
If the brake is pressed first followed
by the accelerator pedal, the driver
input (torque request) is executed.

43
Emergency running program 1
If an angle sender for throttle valve drive fails
or an implausible signal is received:
• Torque-increasing requests on engine, e.g. CCS,
EBC (engine braking control) are suppressed.
• The fault lamp for electrical throttle control K132
comes on.
Prerequisite:
An intact angle sender and plausible
air mass flow. The air mass flow is
indicated by the air mass meter and
the charge pressure sender G31.
Self-diagnosis/emergency running mode
If a fault occurs in the throttle valve control part or in the wiring, three emergency running
programs can be run, depending on fault type.
Emergency running program 2
If the throttle valve drive fails or malfunctions:
• The throttle valve drive is switched off and the
throttle valve goes into the emergency running
position. This results in considerable loss of
power, increased idling speed and possibly also
rough idling .
• Driver inputs are executed as far as possible via
the ignition angle and charge pressure. The
engine shows little response to the throttle.
• The fault lamp for electrical throttle control K132
comes on.
Prerequisite:
Emergency running program 2 is only
run if both angle senders for throttle
valve drive recognise the emergency
running position.
Emergency running program 3
If the throttle valve position is not clearly
recognisable and/or if the throttle valve is not
definitely known to be in the emergency
running position:
• The throttle valve drive is switched off and the
throttle valve goes into the emergency running
position. This results in considerable loss of
power, increased idling speed and possibly also
rough idling.
• The engine speed is limited to approx. 1200 rpm
by restricting the injection.
• The fault lamp for electric throttle control K132
comes on.
Repair work may not be performed on
the throttle valve control part J338! If
G186, G187 or G188 becomes faulty,
unit J338 must be replaced
completely and a
basic setting
performed.

57
Additional signals/interfaces
Additional signals/interfaces to
Motronic ME 7.1
The Motronic receives a large number of
additional signals.
The following overview shows the signal
direction and meaning referred to the Motronic
control unit
Input
signalOutput
signalBidirec-
tionalSignal meaning
·CAN-high, data bus signal for automatic gearbox
·CAN-low, data bus signal for automatic gearbox
·CCS, “set/decelerate“ signal for cruise control system
·CCS, “Off“ signal for without cancellation cruise
control system
·CCS, “On/Off“ signal for with cancellation cruise
control system (master switch)
·CCS, “Resume/accelerate“ signal for cruise control
system
·Road speed signal
·Immobiliser/diagnosis signal
·Air conditioner compressor “On/Off“ signal
·Coolant temperature signal
·Engine speed signal
·Fuel consumption signal
The term “interfaces“ is used to
describe the control unit connections
and wiring connections of the various
control units.