Mitsubishi LANCER EVOLUTION-IV 1998 Workshop Manual page 388

27-22
INSPECTION PROCEDURE 2
AYC warning lamp remains lit up after the engine has
started.
The AYC warning lamp ON circuit is probably short-circuited.
NOTE
This symptom is limited only when AYC-ECU power supply is in normal condition and the diagnosis
code is correct.
Does the AYC warning lamp goes out
when the B-96 AYC-ECU connector
is disconnected?
NO
Check the harness between AYC
warning lamp and AYC-ECU.
OK
Replace combination meter.
INSPECTION PROCEDURE 3
AYC is inoperative.
Unable to start or accelerate on slippery road surfaces.
The hydraulic oil level is probably low, there is an oil leak, the hydraulic unit is defective,
or the torque transfer differential is defective.
NOTE
This symptom is limited only when the diagnosis code is correct.
Check the hydraulic oil level.
OK
Check the AYC for operation.
NG
Check hydraulic pressure.
OK
Is foreign matter trapped in the hydrau-
lic line?
NO
Replace the torque transfer differential.
REAR AXLE –
Troubleshooting <AYC>
YES
Replace AYC-ECU.
NG
Repair
NG
Check for oil leak.
Add hydraulic oil.
OK
Check the AYC fluid.
Replace AYC fluid.
Check the trouble symptom.
Replace the torque transfer differential.
NG
Bleed the system of air.
YES
Repair
Check the trouble symptom.
Replace the hydraulic unit.
Probable cause
D Defective combination meter
D Defective harness (short-circuit)
D Defective AYC-ECU
Probable cause
D Low hydraulic oil level
D Oil leak
D Defective hydraulic unit
D Defective torque transfer differential
OK
NG
OK
NG
NG
NG
Repair
Correct