AUTOMATIC TRANSMISSION
Fault finding - Role of components
23A
23A - 12V3 MR-372-J84-23A000$225.mif
AJ0 BVA
Vdiag No.: 04, 05AUTOMATIC TRANSMISSION
Fault finding - Role of components
The automatic transmission computer performs the following functions:
–Transmission operating mode selection:
According to the vehicle speed and the driver's request expressed by the accelerator pedal position, the automatic
transmission determines the best moment for the gear change. The automatic transmission computer corrects any
driver errors and inhibits engagement of a gear that would cause the engine to over- or under-rev.
–Gear changes:
Taking into account the various input factors, the computer will decide whether to actuate the various solenoid valves
to ensure smooth system operation (automatic transmission clutches, brakes and hydraulics).
The computer is also involved in:
–the gear change quality,
–protecting the automatic transmission in the event of a malfunction.
–Disengaging clutch when stopped:
This function enables creep* to be inhibited temporarily when the vehicle is stationary with a gear engaged and the
brake pedal depressed.
The aim of this function is to reduce drag on the vehicle in order to:
●reduce fuel consumption,
●reduce vehicle vibrations,
Creep*: describes the action of the vehicle moving forwards without acceleration and with a gear engaged.
MR-372-J84-23A000$225.mif
AUTOMATIC TRANSMISSION
Fault finding - Interpretation of faults
23A
23A - 45V3 MR-372-J84-23A000$405.mif
AJ0 BVA
Vdiag No.: 04, 05
DF091
PRESENT
OR
STORED"LS" PRESSURE REGULATION SOLENOID VALVE CIRCUIT
1.DEF: Open circuit or short circuit
NOTESConditions for applying fault finding procedures to stored faults:
The fault is declared present after:
–in the event of short circuit+ or short circuit-:
difference between current measured and solenoid valve control.
–in the event of open circuit:
Current setpoint > 625 mA.
OR
Running command AC086 ""LS" pressure regulation solenoid valve".
Effect on system:
–in the event of short circuit+:
The line pressure is at its minimum value.
lock-up open.
–in the event of open circuit:
No effect
–in the event of short circuit-:
The line pressure is at its maximum value.
Customer complaint:
–in the event of short circuit+:
Fault warning light comes on.
–in the event of open circuit or short circuit-:
Possible increase in fuel consumption.
Possible jolting during gear changes.
Fault warning light comes on.
Use the Wiring Diagrams Technical Note, SCENIC II ph2.
Look for any damage to the harness and check the condition and connection of the automatic transmission
computer and automatic transmission connectors.
If the connection is faulty and there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the wiring, otherwise replace it.
Check for + after ignition feed on connection 5LW of component 754.
If + after ignition feed is present, move on to step 1.
If + after ignition feed is not present, move on to step 8.
AFTER REPAIRDeal with any other faults. Clear the fault memory.
Switch off the ignition, wait 1 minute and carry out a road test followed by another
check with the diagnostic tool.
AJ0_V04_DF091//AJ0_V05_DF091
