PETROL INJECTION
Fault finding - System operation
17B
17B - 16
PETROL INJECTION
Fault finding - System operation
17B
17B - 16V9 MR-372-J84-17B050$094.mif
S3000 Injection
Program No.: AD
Vdiag No.: 4C / 54
4. Engine coolant temperature management
Engine cooling is provided by 1 or 2 fan assemblies (depending on the vehicle layout). The injection computer
requests the UPC to actuate them via the multiplex network.
To provide cooling:
Engine running, GMV1 is requested when the coolant temperature exceeds 99 °C and stops when the coolant
temperature falls below 96 °C. GMV2 is requested when the coolant temperature exceeds 102 °C and stops when
the coolant temperature falls below 99 °C.
With the engine off, only fan assembly 1 may be activated to provide the anti-percolation function (if engine is
stopped when very hot). The anti-percolation function is active with the ignition off for a determined period. During
this period, fan assembly 1 is requested if the coolant temperature exceeds approximately 100 °C and is shut down
if the coolant temperature drops below around 95 °C.
If a fault is detected on the coolant temperature sensor circuit, then fan assembly 1 is requested to operate
continuously.
If the engine coolant temperature goes beyond the warning threshold of 11 8 ° C, the injection computer requests the
instrument panel computer via the multiplex network to illuminate on the coolant temperature warning light until the
coolant temperature falls back below 115 ° C.
In addition to the engine requirements, the injection computer centralises the cooling requirements for the Air
conditioning and BVA/BVR functions.
5. Air conditioning function
The S3000 computer manages a cold loop air conditioning system.
– air conditioning request via multiplex connection,
– acquisition of air conditioning circuit pressure,
– vehicle speed
– air conditioning compressor control,
– fan assembly control request by Protection and Switching Unit.
The injection computer recovers the power absorbed by the air conditioning compressor and the fast idling speed
request using the pressure acquired in the air conditioning circuit.
These signals are necessary for adapting the engine management (idling speed regulation, air flow correction, etc.),
for several reasons:
– air conditioning compressor efficiency,
– sturdier engine to torque bucking caused by compressor activation,
– helping the alternator.
Requests for fan assembly 1 and/or fan assembly 2 are recovered based on the air conditioning circuit pressure and
the vehicle speed. In short, the lower the speed and the higher the pressure, the greater the fan assembly requests.
PETROL INJECTION
Fault finding - System operation
17B
17B - 20
PETROL INJECTION
Fault finding - System operation
17B
17B - 20V9 MR-372-J84-17B050$094.mif
S3000 Injection
Program No.: AD
Vdiag No.: 4C / 54
8. Mileage travelled with fault
These two parameters PR105 Distance travelled with OBD fault warning light on and PR106 Distance travelled
with fault warning light on are used to count the distance travelled with one of the injection fault warning lights lit:
level 1 fault warning light (amber) as well as the OBD warning light.
These counters can be reset to 0 using the diagnostic tool (clear faults command).
9. Inter-system engine functions
The inter-system connections concerning the particular requirements of engine management are as follows:
–OBD warning light illumination request by the instrument panel computer to prevent a pollution fault,
–level 1 warning light illumination request to warn of an operating safety fault relating to the injection system,
–level 2 warning light illumination request to warn of an operating safety fault or provide an engine
overheating alert,
– request for fan assembly activation for engine cooling, but also for the air conditioning and automatic
gearbox,
– air conditioning compressor shut-down request for engine programming requirements such as pulling away,
performance, anti-stalling, overspeed, etc.
– passenger compartment heating resistor shut-down or fixing request for engine programming requirements
such as pulling away, performance, anti-stall, overspeed, etc.
