System operation

1. SYSTEM OPERATION

Composition

The injection system consists of:

• accelerator pedal position potentiometer
• accelerator pedal switch
• TDC sensor
• atmospheric pressure sensor
• intake air temperature sensor
• coolant temperature sensor
• refrigerant pressure sensor
• upstream oxygen sensor
• downstream oxygen sensor
• cruise control command
• steering wheel control
• cruise control on / off command
• brake light switch
• fuel vapour absorber
• injection ECU
• camshaft phaser sensor
• camshaft phaser
• motorised throttle body
• 4 injectors
• 4 pencil coils

Control module

128-pin SAGEM ECU, type "S3000", FLASH EEPROM, controlling injection and ignition.

Multipoint injection in sequential mode.

Links with other ECUs:

• UPC
• UCH
• UCE BVA

Immobiliser

The immobiliser function is managed by the UCH ECU and the engine management ECU.

Before any customer request (badge + button press), the engine management ECU and the UCH ECU exchange CAN authentication frames that allow or prevent engine starting.

If more than 5 consecutive unsuccessful authentication attempts occur, the engine management ECU goes into protection mode (anti-scanning) and no longer attempts to authenticate the UCH ECU. It will only exit this mode if the following sequence of operations is respected:

• the ignition remains on for at least 60 seconds, then
• the message is interrupted, and if
• the injection ECU self-powering period has ended (this duration varies with engine temperature).

Following this, one and only one authentication attempt is permitted. If it fails again, the sequence of operations described above must be repeated.

If the engine management ECU still does not unlock, contact Techline.

Impact detected

If an impact is stored by the injection ECU, switch off the ignition for 10 seconds, then switch it back on to allow the engine to start. Then erase the faults.

Camshaft phaser

The injection ECU controls a camshaft phaser that differs depending on the engine:

K4J engine

No camshaft phaser.

F4R engine

Intake camshaft phaser controlled by a solenoid valve supplied on/off by the injection ECU.

K4M engine

Intake camshaft phaser continuously variable from 0 to 43˚ crankshaft, controlled by a solenoid valve supplied by a variable duty cycle (RCO) circuit from the injection ECU.

IMPORTANT

Disconnect the injection ECU before carrying out any welding on the vehicle.

2. OPERATING SAFETY

Warning light illumination

The S3000 injection system manages the illumination of three warning lights and the display of warning messages according to the severity level of detected faults, in order to inform the customer and guide the diagnosis.

The injection ECU manages the illumination and display of dashboard warning lights and messages. These lights come on during the starting phase, in case of an injection fault or engine overheating.

Warning light requests are sent to the instrument panel via the multiplexed network.

Warning light operating principle

During the starting phase (pressing the "START" button), the "OBD" (On Board Diagnostic) light comes on for about 3 seconds, then goes out.

In case of an injection fault (severity 1), the message "INJECTION TO BE CHECKED" appears, followed by the "SERVICE" warning light coming on. It implies reduced operation and limited safety level.

Repairs must be carried out as soon as possible.

Components concerned:

• motorised throttle body
• accelerator pedal position sensor
• intake pressure sensor
• ECU
• actuator power supply
• ECU power supply

In the event of a serious injection fault (severity 2), the red engine symbol and the word "STOP" (multi-function display only) appear, with the message "ENGINE OVERHEATING", followed by the "STOP" warning light coming on and an audible warning. In this case, the vehicle must be stopped immediately.

When a fault causing excessive exhaust emissions is detected, the orange OBD warning light, symbolised by an engine, comes on:

• flashing in the event of a fault that could cause catalytic converter destruction (destructive misfires). In this case, the vehicle must be stopped immediately.
• steady in the event of non-compliance with emission standards (polluting misfires, catalytic converter fault, oxygen sensor fault, inconsistency between oxygen sensors, or fuel vapour canister fault).

Mileage counter with fault

This parameter counts the distance travelled with one of the injection fault warning lights on: amber severity 1 fault light, engine coolant overheating warning light, or OBD warning light.

This counter can be reset to 0 using the diagnostic tool.

Degraded modes

Electronic throttle body

In limp-home mode, the electronic throttle body can take 6 different states.

State 0

Throttle opening is below the "Limp-home position". The throttle is no longer controlled and automatically goes to the "Limp-home position". The ESP, distance control, cruise control/speed limiter and automatic transmission systems are inhibited.

State 1

Throttle opening is no longer monitored. Engine speed is limited by fuel cut-off.

State 2

Limp-home mode is associated with pedal setpoint reconstruction (constant pedal setpoint depending on gear ratio).

State 3

The associated limp-home mode is a throttle opening limitation. The maximum throttle opening threshold results in a speed below 90 km/h.

State 4

The ECU no longer processes torque change requests from the ESP, distance control, cruise control/speed limiter and automatic transmission systems.

This limp-home mode occurs following an ECU malfunction or a fault with the intake manifold pressure sensor or the boost pressure sensor.

The ESP, distance control and cruise control/speed limiter systems are inhibited. The automatic transmission system is in "limp-home mode".

State 5

The boost control valve no longer operates.

Camshaft phaser

In limp-home mode, the camshaft phaser can take two different states.

State 1

This limp-home mode covers all faults affecting the measurement of the phaser position. The phaser is driven to its low stop and the camshaft angle measurement is forced to 0.

Tooth signal fault.

Tooth / camshaft signal consistency diagnosis.

State 2

This limp-home mode covers all faults affecting the phaser (pulley and solenoid valve). The phaser is driven to its low stop.

Electrical diagnosis of the solenoid valve.

Diagnosis of the phaser position.