PSA AL4 Technical Training

PRESENTATION OF THE AL4
AUTOMATIC TRANSMISSION

DOCUMENT SUMMARY
PRESENTATION OF THE
AL4 AUTOMATIC TRANSMISSION

The aim of this document is to give a brief description of the design and operation
of the electronically managed AL4 automatic transmission which offers precise,
adaptive control as well as excellent gear changing quality.
The following subjects are dealt with in this document:
- Presentation of the transmission and various pieces of information,
- The selector control,
- Lubrication,
- The converter,
- The mechanism,
- The ECU,
- Auto-diagnostics,
- The electrical circuit,
- Unit maintenance.


CONTENTS
CHAPTER 1 : PRESENTATION - GENERAL............................. PAGE 1
I - INTRODUCTION.............................................................................. PAGE 1
II - PRESENTATION............................................................................. PAGE 2
III - DESCRIPTION OF THE AL4 AUTOMATIC TRANSMISSION.......... PAGE 3
IV - IDENTIFYING THE COMPONENTS OF THE AUTOMATIC
TRANSMISSION.............................................................................. PAGE 5
V - SPECIFICATIONS - SERVICING..................................................... PAGE 7
VI - LAYOUT OF THE AL4 AUTOMATIC TRANSMISSION.................... PAGE 8
VII - MISCELLANEOUS ADVICE............................................................. PAGE 9
CHAPTER 2 : SELECTOR CONTROL........................................ PAGE 11
I - SELECTOR LEVER......................................................................... PAGE 11
II - PROGRAM SELECTOR................................................................... PAGE 13
CHAPTER 3 : CHECKING THE OIL LEVEL............................... PAGE 15
CHAPTER 4 : THE TORQUE CONVERTER............................... PAGE 17
I - DESCRIPTION................................................................................. PAGE 17
II - CONVERTER LOCK-UP.................................................................. PAGE 18
CHAPTER 5 : THE EPICYCLIC GEAR TRAIN ........................... PAGE 21
I - DESCRIPTION................................................................................. PAGE 21
II - OPERATING PRINCIPLE ................................................................ PAGE 23
CHAPTER 6 : ECU....................................................................... PAGE 27
I - ECU FUNCTIONS............................................................................ PAGE 27
II - OPERATING SUMMARY................................................................. PAGE 31
III - ECU CONNECTIONS ...................................................................... PAGE 33
CHAPTER 7 : AUTO-DIAGNOSTIC ............................................ PAGE 35
I - FAULT WARNINGS......................................................................... PAGE 35
II - MEMORISED FAULTS / DOWNGRADED MODES.......................... PAGE 36

CHAPTER 8 : WIRING DIAGRAM - XANTIA.............................. PAGE 37
PETROL ENGINE/WITHOUT CRUISE CONTROL
I - LAYOUT........................................................................................... PAGE 37
PETROL ENGINE/WITH CRUISE CONTROL
I - LAYOUT........................................................................................... PAGE 38
DIESEL ENGINE/WITHOUT CRUISE CONTROL
I - LAYOUT........................................................................................... PAGE 39
DIESEL ENGINE/WITH CRUISE CONTROL
I - LAYOUT........................................................................................... PAGE 40
II - PARTS LIST..................................................................................... PAGE 41
CHAPTER 9 : AFTER-SALES OPERATIONS............................ PAGE 43
I - DOWNLOADING.............................................................................. PAGE 43
II - CONFIGURATION........................................................................... PAGE 43
III - PEDAL PROGRAMMING................................................................. PAGE 44
IV - INITIALISING THE "OLD OIL" COUNTER........................................ PAGE 44
V - UPDATING THE "OLD OIL" COUNTER........................................... PAGE 44
VI - TEST AFTER REPAIR WORK......................................................... PAGE 44
VII - CHANGING PARTS, OPERATIONS TO BE PERFORMED............. PAGE 45
VIII - AUTHORISED OPERATIONS DURING THE WARRANTY PERIOD
PAGE........................................................................................... 46
IX - AUTOMATIC TRANSMISSION REPAIR BY THE CITROËN
AUTOMATIC TRANSMISSION CENTRE, SOUTH WEST PARIS.... PAGE 47
X - SPECIAL TOOLING......................................................................... PAGE 50
XI - DIAGNOSTIC TOOLING.............................................................. 51