Workshop Manual

7A–17
AUTOMATIC TRANSMISSION (4L30–E)
Chart 7: Harsh 1–2 Shift
Step
Action
Yes No
1 Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
Check for 1–2
accumulator
valve (320) stuck
by foreign
material in main
case valve body.
Use Chart 15b:
Possible Causes
of High Line
Pressure in this
section.
Chart 8: Harsh 3–4 Shift
Step
Action
Yes No
1 Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
Go to Step 2
Use Chart 15b:
Possible Causes
of High Line
Pressure in this
section
2 1. Check for 3–4 accumulator valve (407) stuck in adapter case
valve body (401).
2. Check for 3–4 accumulator piston (18) stuck in adapter case
(20).
Was the problem found?
Repair or replace —
Chart 9a: 3–2 Downshift Complaint
Step
Action
Yes No
1 Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
Go to Step 2
Use Chart 15a:
Possible Causes
of Low Line
Pressure in this
section
2 Does DTC P1850 set?
Diagnose P1850
first
Replace band
apply solenoid
(PWM) (323)
Chart 9b: Harsh Shift When Shifting Into “D” Or Accelerating From Stop
Step
Action
Yes No
1 Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
Go to Step 2
Use Chart 15b:
Possible Causes
of High Line
Pressure in this
section
2 Does DTC P1850 set?
Diagnose P1850
first
Replace band
apply solenoid
(PWM) (323)