Citroen C5 Aircross Quiz
Cooling

Effect of air conditioning

In this manual: Cooling
AAS - Parking Aid — 8Owner's Manual Citroën C5 II — 139Citroen C5 Aircross (2017- 2024) - Owner's Manual — 143Audio system — 14Overspeed control — 7Multifunction display — 4Driver information instrument cluster — 20Navigation assistance — 8Intruder alarm — 7Mechanical specifications — 9Power supply — 8Electrical equipment — 13Lighting and electrical equipment — 3Immobiliser — 4Sunroof — 10Exterior lighting / signalling — 38Multiplexing — 7Air conditioning — 7Body — 6General specifications — 9Automatic gearbox control — 3Exterior mirrors — 10Airbags — 5Defrost — 6Underinflation — 6Interior lighting — 4Wipers / Washers — 6Window lifters — 11Cooling — 8Opening management — 7Cruise control — 5Suspension — 4Grip management — 1Paint — 2Exterior lighting control — 1Indicators (turn signals) — 1Automatic lighting systems - General recommendations — 1Wiper control — 1Special position of the front wipers — 1
4steps
~24min
2/5difficulty
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Performance

For condenser cooling, the B.R.A.C. function (Cooling Requirement Associated with Refrigeration), internal to the Engine Control Module, sends a speed setpoint to the F.R.I.C. function, depending on the refrigerant circuit pressure.

The linear pressure sensor, located on the condenser, supplies a voltage proportional to the refrigerant circuit pressure.

Block diagram

Incidence de la climatisation
Effect of air conditioning

Key:

  • single arrow: wired link,
  • triple arrow: multiplexed link.
Description fonctionnelle

Functional description

STEP

DETAILS

A

 The Engine Control Module receives the linear pressure sensor signal via a wired link.
The Engine Control Module transmits the refrigerant circuit pressure on the CAN network.

B

 pressure > 10 bar

the Engine Control Module commands low speed of the Cooling Fan Unit.
PRESSURE > 17 bar

the BSI commands medium speed of the Cooling Fan Unit.
PRESSURE > 22 bar

the Engine Control Module commands high speed of the Cooling Fan Unit.
Trait continu : seuils d’enclenchement des vitesses du GMV

Solid line: Cooling Fan Unit speed engagement thresholds

Dotted line: Cooling Fan Unit speed disengagement thresholds

  1. Low speed
  2. Medium speed
  3. High speed
  4. Pressure (in bar)

Degraded mode

A fault in the refrigerant circuit pressure sensor causes the following actions:

  • air conditioning compressor engagement prohibited (controlled by the BSI for air conditioning requirements),
  • a fault is recorded in the Engine Control Module.

The Cooling Fan Unit is no longer available for the cooling requirements associated with air conditioning.

Test yourself

A quick Citroen C5 Aircross quiz: every answer comes with an explanation and a link to the manual page.