AUTOMATIC TRANSMISSION
Fault finding - Introduction
23A
23A-5V3 MR-372-J84-23A000$045.mif
AJ0 BVA
Vdiag No.: 04, 05
4. FAULT FINDING PROCEDURE (continued)
Wiring check
Fault finding problems
Disconnecting the connectors and/or manipulating the wiring may temporarily remove the cause of a fault.
Electrical measurements of voltage, resistance and insulation are generally correct, especially if the fault is not
present when the analysis is made (stored fault).
Visual inspection
Look for damage under the bonnet and in the passenger compartment.
Carefully check the fuses, insulators and wiring harness routing.
Look for signs of oxidation.
Physical inspection
While manipulating the wiring, use the diagnostic tool to note any change in fault status from stored to present.
Make sure that the connectors are properly locked.
Apply light pressure to the connectors.
Twist the wiring harness.
If there is a change in status, try to locate the source of the fault.
Inspection of each component
Disconnect the connectors and check the appearance of the clips and tabs, as well as the crimping (no crimping on
the insulating section).
Make sure that the clips and tabs are properly locked in the sockets.
Check that no clips or tabs have been dislodged during connection.
Check the clip contact pressure using an appropriate model of tab.
Resistance check
Check the continuity of entire lines, then section by section.
Look for a short circuit to earth, to + 12 V or with another wire.
If a fault is detected, repair or replace the wiring harness.
AUTOMATIC TRANSMISSION
23A
23A - 156V3 MR-372-J84-23A000$945.mif
AJ0 BVA
Vdiag No.: 04, 05AUTOMATIC TRANSMISSION
Fault finding - Fault Finding Chart
ALP1 No dialogue with the computer
NOTESSpecial notes:
Only consult this customer complaint after a multiplex network check using the
diagnostic tool.
Make sure that the vehicle + after ignition feed is activated. Check the presence and condition of the UPC automatic
transmission fuses.
Check that the tool is not the cause of the fault, by attempting dialogue with a different system (UCH, Injection,
etc.) on the same vehicle or another vehicle.
Carry out another multiplex network test on the vehicle using the diagnostic tool:
Is the automatic transmission computer recognised?
NO YES
Check that the computer connector is properly
connected and check the condition of its
connections.
Check for the automatic transmission supply fuse on
the passenger compartment connection unit, and its
condition.
Check the battery voltage:
9.5 V < battery voltage < 15.5 V
Carry out the necessary operations to obtain a
correct voltage: Carry out a full check on the battery
and the charging circuit (see Technical
Note 6014A, Charging circuit check).
Establish dialogue with the automatic transmission
computer.
Communication successful at first attempt?
NO YES
Is the identification
screen displayed
after 3 attempts?
End of fault finding.
AFTER REPAIRDeal with any faults detected by the diagnostic tool. Clear the computer memory.
Carry out a road test, then check with the diagnostic tool.
AJ0_V04_ALP01/AJ0_V05_ALP01
MR-372-J84-23A000$945.mif
