A/T Does Not Shift: 5TH Gear->4TH Gear

A/T Does Not Shift: 5th gear -> 4th gear

SYMPTOM: When shifted from M5 to M4 position in manual mode, does not downshift from 5th to 4th gears.

DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSIS RESULTS
Perform self-diagnosis. Refer to "SELF-DIAGNOSTIC PROCEDURE (WITH CONSULT-II)".
Do the self-diagnosis results indicate PNP switch, ATF pressure switch 1?
YES >>Check the malfunctioning system. Refer to "DTC P0705 PARK/NEUTRAL POSITION SWITCH", "DTC P1841 ATF PRESSURE SWITCH 1".
NO >>GO TO 2.

2. CHECK A/T FLUID LEVEL
Check the A/T fluid level.
OK or NG
OK >>GO TO 3.
NG >>Refill ATF.

3. CHECK CONTROL LINKAGE
Check the control linkage.
^ Refer to "Checking of A/T Position".
OK or NG
OK >>GO TO 4.
NG >>Adjust control linkage. Refer to "Adjustment of A/T Position".

4. MANUAL MODE SWITCH
Check the manual mode switch. Refer to "DTC P1815 MANUAL MODE SWITCH".
OK or NG
OK >>GO TO 5.
NG >>Repair or replace damaged parts.

5. CHECK SYMPTOM
Check again.
OK or NG
OK >>INSPECTION END
NG >>GO TO 6.

6. CHECK TCM
Perform TCM input/output signal inspection. Refer to "TCM Input/Output Signal Reference Values".
OK or NG
OK >>INSPECTION END
NG >>GO TO 7.

7. DETECT MALFUNCTIONING ITEM
Check the following items:
^ Power supply and ground circuit for TCM.
^ A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >>Replace the transmission assembly.
NG >>Repair or replace damaged parts.