7A–13 AUTOMATIC TRANSMISSION (4L30–E)
Mechanical / Hydraulic Diagnosis Symptoms Index
Perform Preliminary Inspection First!
CHART
SYMPTOMS
1NO ENGINE START IN NEUTRAL OR PARK
2NO FORWARD GEARS IN ANY RANGE/NO REVERSE
3NO ENGINE BRAKE IN ANY RANGE
4POOR SHIFTING IN ALL GEARS (ALL HARSH OR ALL SOFT)
5aDELAYS IN DRIVE AND REVERSE
5bDELAYS IN REVERSE ONLY
6DIAGNOSTIC TROUBLE CODE (DTC) P0730
7HARSH 1–2 SHIFT
8HARSH 3–4 SHIFT
9a3–2 DOWNSHIFT COMPLAINT
9bHARSH SHIFT WHEN SHIFTING INTO “D” OR ACCELERATING FROM STOP
9cCOASTDOWN HARSH SHIFT OR CLUNK AT 3–2 DOWNSHIFT
10INTERMITTENT 4TH TO 2ND GEAR DOWNSHIFT AT STEADY SPEED
11ENGINE FLARE AT SHIFTING DURING TURNING ONLY (USUALLY WITH WARM ENGINE)
12ENGINE FLARE DURING 1–2 OR 2–3 SHIFT
13SHUDDER ONLY DURING TORQUE CONVERTER CLUTCH (TCC) APPLYING
14POSSIBLE CAUSES OF TRANSMISSION NOISE
15aPOSSIBLE CAUSES OF LOW LINE PRESSURE
15bPOSSIBLE CAUSES OF HIGH LINE PRESSURE
16POSSIBLE CAUSES OF TRANSMISSION FLUID LEAKS
NOTE: Numbers with parenthesis on the following charts
refer to Parts List at end of this section.
Chart 1: No Engine Start In Neutral Or Park
StepActionYe sNo
1Does engine start when shift lever moved from drive to neutral
mostly in hot condition?
Go to Step 2Go to Step 3
2Does engine start in park at any condition?Re–test vehicleGo to Step 4
3Does engine also not start in neutral when shift lever moved from
park to neutral?
Go to Step 4Go to Step 5
4Check mode switch (63) setting. Readjust if necessary.
Problems fixed?
Re–test vehicleGo to Step 5
5Check start circuit of mode switch (63) open in neutral.
Was open found?Locate and repair
open(s)Replace mode
switch (63)
7A–64 AUTOMATIC TRANSMISSION (AW30-40LE)
F07RY00003
TIME LAG TEST
If the shift lever is shifted while the engine is idling, there will be
a cer tain time elapse or lag before the shock can be felt. This is
used for checking the condition of the forward clutch, direct
clutch, No. 3 brake, and No. 2 one-way clutch.
NOTE:
(1) Perform the test at normal operation fluid temperature
(50 – 80
C or 122 – 176F).
(2) Be sure to allow one minute interval between tests.
(3) Make three measurements and take the average value.
MEASURE TIME LAG
1) Fully apply the parking brake.
2) Start the engine.
Check idling speed (A/C OFF)
3) Shift the shift lever from "N" to "D" range. Using a stop
watch, measure the time it takes from shifting the lever until
the shock is felt.
4) In same manner, measure the time lag for "N"
"R".
EVALUATION
1) If "N" "D" time lag is longer than specified:
• Line pressure too low
• Forward clutch malfunction
• No. 2 one-way clutch not operating properly
2) If "N"
"R" time lag is longer than specified:
• Line pressure too low
• Direct clutch malfunction
• No. 3 brake malfunction
3) If both time lag is longer than specified:
• Line pressure too low"N" range 695 – 745 rpm
Time lag Less than 0.7 seconds
Time lag Less than 1.2 seconds
7A–68 AUTOMATIC TRANSMISSION (AW30-40LE)
F07RY00011
F07RY00012
F07RY00020
F07RY00014
F07RY00015
"2" RANGE TEST
Shift into "2" range and, while driving with the accelerator pedal
held constantly at the specified point (throttle valve opening
50% and 100%), push in one of the pattern selectors (only for
4x4) and check on the following points.
1) At each of the above throttle openings, check to see that
the 1
2 up-shift takes place and that the shift points
conform to those shown on the automatic shift diagram.
NOTE:
There is no OD and no lock-up in the "2" range.
2) While running in the "2" range and 2nd gear, release the
accelerator pedal and check the engine's braking effect.
3) Check for 2
1 down-shift and abnormal noise at
acceleration and deceleration, and for shock at upshift and
down-shift.
"L" RANGE TEST
1) While running above 90 km/h (56 mph) in the "D" range,
release your foot from the accelerator pedal and shift into
the "L" range.
Then check to see that the 2
1 and 3 2 down-shift
occurs at the specified point shown on the automatic shift
diagram.
2) While running in the "L" range, check to see that there is no
up-shift to 2nd gear.
3) While running in the "L" range, release the accelerator
pedal and check the engine braking effect.
4) Check for abnormal noise during acceleration and
deceleration.
"R" RANGE TEST
Shift into the "R" range and, while starting at full throttle, check
for slipping.
"P" RANGE TEST
Stop the vehicle on a grade (more than 9%) and after shifting
into the "P" range, release the parking brake. Then check to
see that the parking lock pawl holds the vehicle in place.
