A/T Does Not Shift: D5 -> D4

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.

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". P0705 P1841
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.
^ Refer to "Checking of A/T Position".

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.