Chrysler 300M 2002 Service Manual page 2801

GENERAL INFORMATION
energizing the transmission control relay, and tak-
ing power from the solenoid pack. When this hap-
pens, the only transaxle mechanical functions are:
Park and Neutral
Reverse
Second Gear
No upshifts or downshifts are possible. The position
of the manual valve alone allows the three ranges
that are available. Although vehicle performance is
seriously degraded while in this mode, it allows the
owner to drive the vehicle in for service.
Once the DRBIII is in the Transmission portion
of the diagnostic program, it constantly monitors
the PCM to see if the system is in Limp-in mode. If
the transaxle is in Limp-in mode, the DRBIII will
flash the red LED.
3.2.1 AUTOSTICK FEATURE (IF
EQUIPPED)
This feature allows the driver to manually shift
the transaxle when the shift lever is pulled into the
AutoStick position. When in AutoStick mode, the
instrument cluster displays the current gear.
3.2.2 TRANSMISSION OPERATION AND
SHIFT SCHEDULING AT VARIOUS
OIL TEMPERATURES
The transmission covered in this manual has
unique shift schedules depending on the tempera-
ture of the transmission oil. The shift schedule is
modified to extend the life of the transmission while
operating under extreme conditions.
The oil temperature is measured with a Tempera-
ture Sensor on the 42LE transmission. The Temper-
ature Sensor is an integral component of the Trans-
mission Range Sensor (TRS). If the Temperature
Sensor is faulty, the transmission will default to a
calculated oil temperature DTC P1799(74). Oil tem-
perature will then be calculated through a complex
heat transfer equation using engine coolant temper-
ature, battery/ambient temperature, and engine off
time from the Body Control Module (BCM). These
inputs are received from the PCI bus periodically
and used to initialize the oil temperature at start
up. Once the engine is started, the PCM updates
the transmission oil temperature based on torque
converter slip speed, vehicle speed, gear, and engine
coolant temperature to determine an estimated oil
temperature during vehicle operation. Vehicles us-
ing calculated oil temperature track oil tempera-
ture reasonably accurate during normal operation.
However, if a transmission is overfilled, a transmis-
sion oil cooler becomes restricted, or if a customer
drives aggressively in low gear, the calculated oil
temperature will be inaccurate. Consequently the
shift schedule selected may be inappropriate for the
current conditions. The key highlights of the vari-
ous shift schedules are as follows:
Extreme Cold: Oil temperature at start up be-
low 26.6°C (-16°F)
> Goes to Cold schedule above -24°C (-12°F) oil
temperature
> Park, Reverse, Neutral and 2
(prevents shifting which may fail a clutch
with frequent shifts)
Cold: Oil temperature at start up above -24°C
(-12°F) and below 2.2°C (36°F)
> Goes to Warm schedule above 4.4°C (40°F) oil
temperature
> Delayed 2-3 upshift approximately 35-50
Km/h (22 - 31 MPH)
> Delayed 3-4 upshift 72-85 Km/h (45-53 MPH)
> Early 4-3 coastdown shift approximately 48
Km/h (30 MPH)
> Early 3-2 coastdown shift approximately 27
Km/h (17 MPH)
> High speed 4-2, 3-2, 2-1 kickdown shifts are
prevented
> No EMCC
Warm: Oil temperature at start up above 2.2°C
(36°F) and below 27°C (80°F)
> Goes to a Hot schedule above 27°C (80°F) oil
temperature
> Normal operation (upshifts, kickdowns, and
coastdowns)
> No EMCC
Hot: Oil temperature at start up above 27°C
(80°F)
> Goes to a Overheat schedule above 115°C
(240°F) oil temperature
> Normal operation (upshifts, kickdowns, and
coastdowns)
> Full EMCC, No PEMCC except to engage
FEMCC, except at closed throttle at speeds
above 113-133 Km/h (70-83 MPH)
Overheat: Oil temperature above 115°C (240°F)
or engine coolant temperature above 115°C (240°F)
> Goes to a Hot below 110°C (230°F) oil temper-
ature or a Super Overheat above 135°C
(275°F) oil temperature
> Delayed 2-3 upshift 40-51 Km/h (25-32 MPH)
> Delayed 3-4 upshift 66-77 Km/h (41-48 MPH)
nd
> 2 gear PEMCC above 35 Km/h (22 MPH)
> Above 35 Km/h (22 MPH) the torque converter
will not unlock unless the throttle is closed
(i.e. at 80 km/h (50 MPH) a 4
2
nd
gear only
th rd
FEMCC to 3