Mitsubishi Evolution X. Manual - part 890
REAR AXLE DIAGNOSIS <AYC>
TSB Revision
REAR AXLE
27-21
Code No. C1620 AYC control abnormality
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnostic trouble code may be set.
Prior to this diagnosis, diagnose the CAN bus
lines.
.
OPERATION
• The power from AWC-ECU is supplied to and
energizes the hydraulic unit AYC proportioning
valve and direction valve (RH/LH) solenoid.
.
FUNCTION
• The AWC-ECU controls the specified current of
the coil for the hydraulic unit AYC proportioning
valve solenoid, and activation command of the
coil for the AYC direction valve (RH/LH) solenoid.
• The hydraulic unit AYC proportioning valve and
direction valve (RH/LH) solenoid control the
hydraulic pressure to the AYC differential right/left
clutch.
.
TROUBLE JUDGMENT
Range of check
• The forced activation of actuator is not underway.
• The output to the AYC proportioning valve sole-
noid is 0.05 A or more.
JUDGMENT CRITERIA
• Due to the AYC differential clutch protection, DTC
No. C161F is set.
• The AYC proportioning valve solenoid is ener-
gized longer than the specified duration.
Fail-safe, backup function
• The AWC-ECU suspends the AYC control and
illuminates the multi-information display. Then
DTC No. C1620 is set.
.
PROBABLE CAUSES
• The driving and road conditions are severe.
• Malfunction inside the AWC-ECU
DIAGNOSTIC PROCEDURE
STEP 1. CAN bus diagnostics using the scan tool
Using the scan tool, diagnose the CAN bus lines.
Q: Is the check result normal?
YES :
Go to Step 3.
NO :
Repair the CAN bus line (Refer to GROUP
54C
− Troubleshooting
). After
repairing the CAN bus line, go to Step 2.
STEP 2. DTC recheck after repairing the CAN bus
line
(1) Erase the DTC.
(2) Turn the ignition switch from the LOCK (OFF)
position to the ON position.
(3) Check if the DTC is set.
Q: Is DTC No. C1620 set?
YES :
Go to Step 3.
NO :
This diagnosis is complete.
STEP 3. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Turn the ignition switch from the LOCK (OFF)
position to the ON position.
(3) Check if the DTC is set.
Q: Is DTC No. C1620 set?
YES :
Replace the AWC-ECU (refer to
), and check that another DTC is
not set. Then go to Step 4.
NO :
This diagnosis is complete. Under the
driving and road conditions where the AYC
control is operated long time (e.g.: long time
cornering), the clutch protection is operated.
STEP 4. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Turn the ignition switch from the LOCK (OFF)
position to the ON position.
Q: Is DTC No. C1620 set?
YES :
Diagnose again from Step 1.
NO :
This diagnosis is complete.