Chrysler 1997 Stratus Convertible RHD Service Manual page 974

21 - 6 TRANSAXLE
DIAGNOSIS AND TESTING (Continued)
• Improper adjustments
• Hydraulic malfunctions
• Mechanical malfunctions
• Electronic malfunctions
Diagnosis of these problems should always begin
by checking the easily accessible variables: fluid level
and condition, gearshift cable adjustment. Then per-
form a road test to determine if the problem has been
corrected or that more diagnosis is necessary. If the
problem persists after the preliminary tests and cor-
rections are completed, hydraulic pressure checks
should be performed.
ROAD TEST
Prior to performing a road test, check the fluid
level.
During the road test, the transaxle should be oper-
ated in each position to check for slipping and any
variation in shifting. During test drive the transmis-
sion sump temperature should be monitored for nor-
mal values. Sump temperatures in excess of 230°F
should prompt a thorough oil level and cooling sys-
tems check. RPM monitors should also be watched
for lock-up and gear shifting.
If vehicle operates properly at high speeds, but has
poor acceleration, the converter's overrunning clutch
may be slipping. If acceleration is normal, but high
throttle opening is needed for high speeds, the clutch
may have seized. Both of these stator defects require
replacement of the torque converter.
The clutch that is slipping can be determined by
checking for a DTC code 50–54 and noting the tran-
saxle operation in all selector positions. Then com-
paring which internal units are applied in those
positions. The Elements in Use Chart provides a
basis for road test analysis.
The process of elimination can be used to detect
any unit which slips and to confirm proper operation
of good units. Road test analysis can usually diag-
nose slipping units. However, the actual cause of the
malfunction may not be detected. Practically any con-
dition can be caused by leaking hydraulic circuits or
sticking valves.
HYDRAULIC PRESSURE TESTS
Pressure testing is a very important step in the
diagnostic procedure. These tests usually reveal the
cause of most transaxle problems.
Before performing pressure tests, be certain that
fluid level and condition, and shift cable adjustments
have been checked and approved. Fluid must be at
operating temperature (150 to 200 degrees F.).
Install an engine tachometer, raise vehicle on hoist
which allows front wheels to turn, and position
tachometer so it can be read.
Attach 150 psi gauges to ports required for test
being conducted. A 300 psi gauge (C-3293) is required
for reverse pressure test.
Test port locations are shown in (Fig. 3).
TEST ONE-SELECTOR IN LOW 1st GEAR
(1) Attach pressure gauge to the low/reverse clutch
tap.
(2) Move selector lever to the (L) position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
to 20 mph.
(4) Low/reverse clutch pressure should read 115 to
145 psi.
(5) This test checks pump output, pressure regula-
tion and condition of the low/reverse clutch hydraulic
circuit and shift schedule.
TEST TWO-SELECTOR IN DRIVE 2nd GEAR
NOTE: This test checks the underdrive clutch
hydraulic circuit as well as the shift schedule.
(1) Attach gauge to the underdrive clutch tap.
(2) Move selector lever to the 3 position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 30 mph.
(4) In second gear the underdrive clutch pressure
should read 110 to 145 psi.
TEST 2A–SELECTOR IN OD
NOTE: This test checks the underdrive clutch
hydraulic circuit as well as the shift schedule.
(1) Attach gauge to the UD clutch tap.
(2) Move selector lever to the OD position.
(3) Allow wheels to rotate freely and increase
throttle opening to achieve an indicated speed of 40
mph.
(4) Underdrive clutch pressure should read below
5 psi. If not, than either the solenoid assembly or
TCM is at fault.
TEST THREE-OVERDRIVE CLUTCH CHECK
(1) Attach gauge to the overdrive clutch tap.
(2) Move selector lever to the (Circle D) position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 20 mph.
(4) Overdrive clutch pressure should read 74 to 95
psi.
(5) Move selector lever to the (3) position and
increase indicated vehicle speed to 30 mph.
(6) The vehicle should be in second gear and over-
drive clutch pressure should be less than 5 psi.
JX