Dodge RAM 1500 1998 Owner's Manual page 2108

DR
TORQUE CONVERTER (Continued)
(9) Fill the transmission with the recommended
fluid.
Fig. 125 Checking Torque Converter Seating-Typical
1 - SCALE
2 - STRAIGHTEDGE
TRANSMISSION CONTROL
RELAY
DESCRIPTION
The relay is supplied fused B+ voltage, energized
by the TCM, and is used to supply power to the sole-
noid pack when the transmission is in normal oper-
ating mode.
OPERATION
When the relay is "off", no power is supplied to the
solenoid pack and the transmission is in "limp-in"
mode. After a controller reset, the TCM energizes the
relay. Prior to this, the TCM verifies that the con-
tacts are open by checking for no voltage at the
switched battery terminals. After this is verified, the
voltage at the solenoid pack pressure switches is
checked. After the relay is energized, the TCM mon-
itors the terminals to verify that the voltage is
greater than 3 volts.
AUTOMATIC TRANSMISSION - 45RFE/545RFE
TRANSMISSION RANGE
SENSOR
DESCRIPTION
The Transmission Range Sensor (TRS) is part of
the solenoid module, which is mounted to the top of
the valve body inside the transmission.
The Transmission Range Sensor (TRS) has five
switch contact pins that:
• Determine shift lever position
• Supply ground to the Starter Relay in Park and
Neutral only.
• Supply +12 V to the backup lamps in Reverse only.
The TRS also has an integrated temperature sen-
sor (thermistor) that communicates transmission
temperature to the TCM and PCM.
OPERATION
The Transmission Range Sensor (TRS) communi-
cates shift lever position to the TCM as a combina-
tion of open and closed switches. Each shift lever
position has an assigned combination of switch states
(open/closed) that the TCM receives from four sense
circuits. The TCM interprets this information and
determines the appropriate transmission gear posi-
tion and shift schedule.
There are many possible combinations of open and
closed switches (codes). Seven of these possible codes
are related to gear position and five are recognized
as "between gear" codes. This results in many codes
which should never occur. These are called
"invalid" codes. An invalid code will result in a DTC,
and the TCM will then determine the shift lever
position based on pressure switch data. This allows
reasonably normal transmission operation with a
TRS failure.
GEAR
Park
Temp 1
Reverse
Temp 2
Neutral 1
Neutral 2
Temp 3
Drive
Temp 4
Manual 2
Temp 5
Manual 1
C5 C4 C3
CL OP OP
CL OP OP
OP OP OP
OP OP CL
OP OP CL
OP CL CL
OP CL CL
OP CL CL
OP CL OP
CL CL OP
CL OP OP
CL OP CL
21 - 405
C2 C1
CL CL
CL OP
CL OP
CL OP
CL CL
CL CL
CL OP
OP OP
OP OP
OP OP
OP OP
OP OP