A/T Does Not Shift: D4 -> D3

A/T Does Not Shift: 4th gear -> 3rd gear

SYMPTOM: When shifted from M4 to M3 position in manual mode, does not downshift from 4th to 3rd gears.

DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSIS RESULTS
Perform self-diagnosis.

Do the self-diagnosis results indicate PNP switch, ATF pressure switch 1, ATF pressure switch 3?
YES >> Check the malfunctioning system. Refer to "DTC P0705 PARK/NEUTRAL POSITION SWITCH", "DTC P1841 ATF PRESSURE SWITCH 1", "DTC P1843 ATF PRESSURE SWITCH 3". P0705 P1841 P1843
NO >> GO TO 2.

2. CHECK A/T FLUID LEVEL
Check the A/T fluid level again.

OK or NG
OK >> GO TO 3.
NG >> Refill ATF.

3. CHECK CONTROL LINKAGE
Check the control linkage.

OK or NG
OK >> GO TO 4.
NG >> Adjust control linkage.

4. MANUAL MODE SWITCH
Check the manual mode switch. Refer to "DTC P1815 MANUAL MODE SWITCH". P1815

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.

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.