Chrysler Concorde 2004 Service Manual page 1618

8E - 10 ELECTRONIC CONTROL MODULES
POWERTRAIN CONTROL MODULE (Continued)
Fig. 6 Example of CVI Calculation
1 - OUTPUT SPEED SENSOR
2 - OUTPUT SHAFT
3 - CLUTCH PACK
4 - SEPARATOR PLATE
5 - FRICTION DISCS
6 - INPUT SHAFT
7 - INPUT SPEED SENSOR
8 - PISTON AND SEAL
Clutch
L/R
2/4
OD
UD
TRANSMISSION CONTROL
SHIFT SCHEDULES
The PCM has programming that allows it to select
a variety of shift schedules. Shift schedule selection
is dependent on the following:
• Shift lever position
• Throttle position
CLUTCH VOLUMES
Shift Sequence Oil Temperature
2-1 or 3-1 coast
downshift
1-2 shift
2-3 shift
4-3 or 4-2 shift
For example, if the input shaft is rotating at 1000
rpm and the output shaft is rotating at 500 rpm,
then the PCM can determine that the gear ratio is
2:1. In direct drive (3rd gear), the gear ratio changes
to 1:1. The gear ratio changes as clutches are applied
and released. By monitoring the length of time it
takes for the gear ratio to change following a shift
request, the PCM can determine the volume of fluid
used to apply or release a friction element.
The volume of transmission fluid needed to apply
the friction elements are continuously updated for
adaptive controls. As friction material wears, the vol-
ume of fluid need to apply the element increases.
Certain mechanical problems within the input
clutch assembly (broken return springs, out of posi-
tion snap rings, excessive clutch pack clearance,
improper assembly, etc.) can cause inadequate or out-
of-range element volumes. Also, defective Input/Out-
put Speed Sensors and wiring can cause these
conditions. The following chart identifies the appro-
priate clutch volumes and when they are monitored/
updated:
When Updated
> 70°
> 110°
• Engine load
• Fluid temperature
• Software level
As driving conditions change, the PCM appropri-
ately adjusts the shift schedule. Refer to the follow-
ing chart to determine the appropriate operation
expected, depending on driving conditions.
Throttle Angle
< 5°
5 - 54°
> 5°
LH
Proper Clutch
Volume
35 to 83
20 to 77
48 to 150
24 to 70