Exhaust gas recirculation (EGR)

F8Q engine

1. 1
   EGR valve
2. 2
   EGR solenoid valve (ON/OFF)
3. 3
   Vacuum pump
4. 4
   Engine
5. 5
   Exhaust manifold
6. 6
   Intake manifold
7. 7
   Air filter
8. 8
   Injection ECU
9. 9
   Coolant temperature sensor

To remove the EGR solenoid valve (2), remove the air filter.

To remove the EGR valve (1), remove the air filter. Replace the gasket between the solenoid valve and the manifold each time it is removed.

SPECIFIC FEATURES

To remove the steel pipe connecting the EGR valve to the air filter, the EGR valve must be removed first.

The EGR function is controlled by the ECU via an ON/OFF solenoid valve.

The parameters that determine activation of the EGR solenoid valve are as follows:

• intake air temperature,
• coolant temperature,
• altitude,
• throttle/load lever position,
• vehicle speed,
• engine speed.

EGR is cut off if:

• intake air temperature < 16°C, or
• coolant temperature < 45°C, or
• the engine speed/load potentiometer combination is above a threshold.

EGR cuts out after 40 seconds of idle operation (vehicle speed zero).

As soon as the vehicle speed exceeds 40 km/h, EGR becomes operational again. It will cut out again after 40 seconds of idling at zero vehicle speed.

The right-hand bar of bar graph 14 lights if the EGR function is enabled. To check whether EGR is actually being commanded, run #24: if the value is different from 0, EGR is being commanded.