Idle speed

K9K

To maintain idle speed at the target value, the engine management ECU calculates engine idle speed to compensate for any mechanical or electrical torque variation, based on:

• coolant temperature,
• battery voltage,
• the gear engaged,
• electrical consumers (air conditioning, cooling fan assembly, cabin heater resistors, etc.),
• any faults detected.

Note: At normal engine operating temperature, with no major electrical consumers, engine idle speed is 805 rpm +/- 5.

I - IDLE SPEED CORRECTION BASED ON ENGINE COOLANT TEMPERATURE

X: Engine idle speed (rpm)
Y: Engine coolant temperature (°C)

II - IDLE SPEED CORRECTION IN THE EVENT OF AN ACCELERATOR PEDAL POTENTIOMETER FAULT

• If one or both tracks of the accelerator pedal potentiometer are faulty, the engine management ECU sets idle speed to 1300 rpm.

This limp-home mode results in reduced performance.

The "Injection to be checked" message illuminates, followed by the "Service" warning light.

• If the accelerator pedal potentiometer is stuck, no longer powered, or no longer sends an output signal, the engine management ECU sets idle speed to 1300 rpm. This limp-home mode results in reduced performance. The "Injection to be checked" message illuminates, followed by the "Service" warning light.
• If there is a discrepancy between the accelerator pedal potentiometer signal and the brake switch signal, the injection ECU sets the engine idle speed to 1300 rpm.

III - ENGINE IDLE SPEED CORRECTION IN CASE OF AN INJECTOR C2I CODING ERROR

If there is a coding error in the C2I (individual injector flow correction) of an injector, the injection ECU maintains the engine idle speed at 1300 rpm. This limp-home mode reduces engine performance. The message "Injection to be checked" lights up, followed by the "Service" warning light.

IV - ENGINE IDLE SPEED CORRECTION, VEHICLE MOVING

At normal engine operating temperature, the engine idle speed changes according to the gear engaged:

• in neutral, the speed is 805 rpm,
• in 1st and 2nd gear, the speed is 875 rpm,
• in 3rd and 4th gear, the speed is 900 rpm,
• in 5th gear, the speed is 950 rpm.

F9Q

I - IDLE SPEED CORRECTION BASED ON ENGINE COOLANT TEMPERATURE

In all cases, this engine idle speed correction is deactivated 10 minutes after the engine starts and then takes the value of 800 rpm.

X: Engine idle speed (rpm)
Y: Engine coolant temperature (°C)

II - IDLE SPEED CORRECTION IN THE EVENT OF AN ACCELERATOR PEDAL POTENTIOMETER FAULT

If both tracks of the accelerator pedal potentiometer are faulty, the injection ECU sets the engine idle speed to 1400 rpm. When the brake pedal is pressed, the engine idle speed drops to 1000 rpm.

If there is a discrepancy between the accelerator pedal potentiometer and brake switch signals, the engine idle speed is forced to 1400 rpm.

III - ENGINE IDLE SPEED CORRECTION, VEHICLE MOVING

The engine idle speed when the vehicle is moving is:

• 870 rpm when 1st gear is engaged,
• 850 rpm when 2nd gear is engaged and the vehicle is moving faster than 2.5 km/h,
• 870 rpm when a gear higher than 2nd is engaged.