Preliminaries

1. APPLICABILITY OF THIS DOCUMENT

This document presents the diagnosis applicable to all Electronic Control Units with the following characteristics:

Vehicle: Mégane II. Function concerned: Air conditioning

2. ESSENTIAL ITEMS FOR DIAGNOSIS

Documentation type:

Diagnostic methods (this document and the technical notes for the injection fitted to the vehicle, the Passenger Compartment Unit and the Protection and Switching Unit):

• -\ Assisted diagnosis (built into the diagnostic tool), paper (Repair Manual or Technical Note), Dialogys.

Wiring diagrams:

• Visu-Schéma (CD-ROM), paper.

Diagnostic tool type:

• CLIP

Essential tool type:

3. REMINDERS

Faults:

There are declared faults and stored faults that are present (occurred under a certain context and still present), and stored faults (occurred under a certain context and have since disappeared, or are still present but not diagnosed under the current context).

The "current" or "stored" fault status must be checked when starting the diagnostic tool after switching on ignition (without operating any components of the system).

For a present fault, deal with the fault following the procedure given in the chapter "Fault interpretation".

For a stored fault, note the displayed faults and follow the instructions in the "Instructions" section.

If the fault is confirmed when the instruction is applied, the fault is present. In this case, repair the fault.

If the fault is not confirmed, carry out the basic checks. To do so, check:

• The electrical wiring related to the fault.
• The connectors of these circuits (corrosion, bent pins, etc.).
• The resistance of the component identified as faulty.
• The condition of the wiring (melted or cut insulation, chafing).

Conformity check

The conformity check aims to verify the states and parameters that show no fault on the diagnostic tool when they are inconsistent. This step therefore allows you to:

• diagnose faults with no fault display that may correspond to a customer complaint,
• verify correct operation of the system and make sure a fault will not reappear after repair.

This chapter therefore contains a diagnosis of states and parameters, under the conditions required for their check.

If a state does not operate normally or a parameter is out of tolerance, refer to the corresponding diagnostic page.

Particularities of conformity checks for the air conditioning function:

The conformity check of the air conditioning function is divided into four parts. These parts cover the four sub-functions of the air conditioning function: heating, cooling loop, user selection and passenger compartment ventilation.

The states and parameters concerned by these sub-functions are classified with their respective control unit.

Particularities: the manual air conditioning control panel does not control any electrical components and cannot be diagnosed. Consequently, there is no conformity check in chapter 62C "Manual air conditioning".

NOTE: The interpretation of states, parameters and commands is also spread across several chapters. Everything managed by the air conditioning control panel is interpreted in the two chapters 62A and 62B "Air conditioning". However, information from other ECUs is interpreted in the "diagnosis" chapters of those ECUs (see the conformity check).

Customer complaints - Fault locating tree

If the diagnostic tool check is correct but the customer complaint is still present, treat the problem as a "customer symptom".

4. DIAGNOSTIC PROCEDURE

5. DIAGNOSTIC SHEET

ATTENTION: For any reimbursement of a "under monitoring" part (control module type) or a Techline call, a properly documented diagnostic sheet will be required. This sheet allows you to obtain and keep a record of your diagnosis.

All incidents requiring replacement of a control module must be subject to a complete diagnosis using the appropriate tools. The diagnostic sheet, to be completed during the diagnosis, allows more effective communication with the manufacturer by enabling:

• Faster and more relevant Techline assistance.
• A part change approval request that is better taken into account and better analysed.
• A better description of your findings for guaranteed proper reimbursement.

6. SAFETY INSTRUCTIONS

Any operation on a component requires compliance with safety rules to avoid any material damage or personal injury:

• Check that the battery is correctly charged to avoid damage to the ECUs in case of low charge.
• No smoking.
• Use the appropriate tools.