Renault Megane Quiz
Electrical equipment

Preliminaries

In this manual: Electrical equipment
Engine and peripherals — 141Chassis — 79Chassis — 72Renault Mégane III Driver's Manual — 87Electrical equipment — 221Engine and peripherals — 47Electrical equipment — 80Transmission — 14Air conditioning — 30Bodywork — 115Trim and upholstery — 44General vehicle information — 27Air conditioning — 59General vehicle information — 16Transmission — 38Sealing and soundproofing — 7General vehicle information — 3
~7min read

1. APPLICABILITY OF THIS DOCUMENT

This document describes the diagnosis applicable to all control units with the following characteristics:

Vehicle: MEGANE II TYPE BMXX, CMXX AND SMXX
Function concerned: AIRBAG		 Control unit name: AUTOLIV - ACU 4
Program No.:
Vdiag No.: 04

2. ESSENTIAL ITEMS FOR DIAGNOSIS

Documentation type

Diagnostic methods (this document):

  • 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

ESSENTIAL SPECIALIST TOOLS
  • Multimeter
  • Collection of adapters and terminal blocks for using the “Airbag and pretensioner harness check” function of the CLIP or XRBAG tools, at the update level including the terminal blocks listed below.
  • The series change to the new airbag igniter connectors requires a change to the inert igniter.

LOCAL MODIFICATION OF THE INERT IGNITER:

  • Remove the igniter from its red holder and remove one of the two brown locking notches.
  • Control unit terminal block 22-way: Elé. 1685
  • Control unit terminal block 64-way: Elé. 1686
  • Seat terminal block 22-way: Elé. 1687
  • Rotary contact terminal block 10-way: Elé. 1617

3. REMINDERS

Faults

Procedure

To diagnose the vehicle's control units, put the ignition in diagnostic mode (+ after forced ignition):

  • Place the vehicle badge on the badge holder.
  • long press (more than 5 seconds) on the "start" button outside starting conditions,
  • Then connect the diagnostic tool and carry out the required operations.
IMPORTANT

The left and right xenon headlamp control units are powered when the dipped beam headlights are switched on.

Their diagnosis is therefore only possible after switching the ignition on in diagnostic mode (or after forced ignition) and switching on the dipped headlights.

To switch off the +after ignition, proceed as follows:

  • Disconnect the diagnostic tool,
  • Briefly press the "start" button twice (less than 3 seconds each time),
  • Check that the +after ignition forced is switched off by the computer warning lights on the instrument panel going out.

There are declared present faults and declared stored faults (which appeared under certain conditions and have since cleared, or are still present but were not diagnosed under the current conditions).

The “present” or “stored” state of faults must be considered when the diagnostic tool is started after + after ignition (without any action on the system components).

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 circuits corresponding to the fault,
  • the connectors of these lines (corrosion, bent pins, etc.),
  • the resistance of the component detected as faulty,
  • the condition of the wiring (melted or cut insulation, chafing),

or use the diagnosis as a guide to check the circuit of the suspect component.

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.

Customer complaints - Fault locating tree

If the diagnostic tool check is correct but the customer complaint is still present, deal with the problem using "customer complaints".

A summary of the overall procedure is shown as a flowchart on the next page.

4. DIAGNOSTIC PROCEDURE

Préliminaires

5. DIAGNOSTIC SHEET

WARNING:

For any reimbursement of a “monitored” part (control unit type) or any Techline call, a properly documented diagnostic record will be required.

A DIAGNOSTIC SHEET MUST BE COMPLETED EVERY TIME A DIAGNOSIS IS PERFORMED.

All incidents requiring control unit replacement must be subject to a complete diagnosis using suitable tools. The diagnostic record must be completed during the diagnosis and is used to report findings for warranty reimbursement.

6. SAFETY INSTRUCTIONS

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

  • Check that the battery is correctly charged to avoid damage to the ECUs in case of low charge.

When working on airbag and seat belt pretensioner systems, always lock the control unit using the diagnostic tool to prevent any risk of accidental deployment (all firing lines will be inhibited). This “locked” mode is indicated by the warning light on the instrument panel coming on.

If the diagnostic tool cannot connect, switch off the ignition, remove the system's power fuse and wait at least 2 seconds for the reserve energy capacitor to discharge.

Never take measurements on the airbag and pretensioner firing lines with any device other than the XRBAG or the “Airbag and pretensioner harness check” function of the CLIP.

Before using an inert igniter, make sure its resistance is between 1.8 and 2.5 Ω.

During the procedure, make sure the control unit supply voltage does not drop below 10 V.

WARNING

The destruction and disposal of airbags and pretensioners is subject to the legislation of each country.

SYSTEM CONFIGURATION SHEET (FRONT PART)

Préliminaires

RR To rear wiring harness

SYSTEM CONFIGURATION SHEET (REAR PART)

Préliminaires
Préliminaires
Préliminaires

Correct insulation value: display ≥ 100.h or flashing 9999.

DEFINITION OF FIRING LINES

L1: Driver seat cushion / lap belt airbag circuit (wire B of 64-way connector Elé. 1686)
L2: Passenger seat cushion / lap belt airbag circuit (wire D of 64-way connector Elé. 1686)
L3: Front passenger airbag circuit 1 (wire B of 22-way connector Elé. 1685)
L4: Front passenger airbag circuit 2 (wire A of 22-way connector Elé. 1685)
L5: Driver front airbag circuit 1 (wire C of 22-way connector Elé. 1685)
L6: Driver front airbag circuit 2 (wire D of 22-way connector Elé. 1685)
L7: Driver side head airbag circuit (wire I of 64-way connector Elé. 1686)
L8: Passenger side head airbag circuit (wire G of 64-way connector Elé. 1686)
L9: Driver front side thorax airbag circuit (wire H of 64-way connector Elé. 1686)
L10: Passenger front side thorax airbag circuit (wire F of 64-way connector Elé. 1686)
L11: Driver rear side thorax airbag circuit (wire N of 64-way connector Elé. 1686)
L12: Passenger rear side thorax airbag circuit (wire L of 64-way connector Elé. 1686)
L13: Front belt pretensioner circuits (wires A and C of 64-way connector Elé. 1686)
L14: Rear retractors (wires E and J of 64-way connector Elé. 1686)

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