The 545RFE automatic transmission is a sophisticated, multi-range, electronically controlled transmission which
combines optimized gear ratios for responsive performance, state of the art efficiency features and low NVH. Other
features include driver adaptive shifting and three planetary gear sets to provide wide ratio capability with precise
ratio steps for optimum driveability. The three planetary gear sets also make available a unique alternate second
gear ratio. The primary 2nd gear ratio fits between 1st and 3rd gears for normal through-gear accelerations. The
alternate second gear ratio (2prime) allows smoother 4-2 kickdowns at high speeds to provide 2nd gear passing
performance over a wider highway cruising range. An additional overdrive ratio (0.67:1) is also provided for greater
fuel economy and less NVH at highway speeds.

The hydraulic portion of the transmission consists of the transmission fluid, fluid passages, hydraulic valves, and
various line pressure control components.

The primary mechanical components of the transmission consist of the following:

•

Three multiple disc input clutches

•

Three multiple disc holding clutches

•

Five hydraulic accumulators

•

Three planetary gear sets

•

Dual Stage Hydraulic oil pump

•

Valve body

•

Solenoid pack

The Transmission Control Module (TCM) is the “heart” or “brain” of the electronic control system and relies on infor-
mation from various direct and indirect inputs (sensors, switches, etc.) to determine driver demand and vehicle oper-
ating conditions. Depending on the vehicle configuration, the TCM may be a standalone module or it it may be
housed along with the Powertrain Control Module (PCM) in a single module. With this information, the TCM can
calculate and perform timely and quality shifts through various output or control devices (solenoid pack, transmission
control relay, etc.).

AUTOMATIC TRANSMISSION 545RFE - SERVICE INFORMATION

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TRANSMISSION IDENTIFICATION

Transmission identification numbers (1) are stamped
on the left side of the case just above the oil pan seal-
ing surface. Refer to this information when ordering
replacement parts. A label is attached to the transmis-
sion case above the stamped numbers. The label
gives additional information which may also be neces-
sary for identification purposes.

GEAR RATIOS

The 545RFE gear ratios are:

1st . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.00:1
2nd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.67:1
2nd Prime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.50:1
3rd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.00:1
4th . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.75:1
5th . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.67:1
Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.00:1

OPERATION

The 545RFE offers full electronic control of all automatic up and downshifts, and features real-time adaptive closed-
loop shift and pressure control. Electronic shift and torque converter clutch controls help protect the transmission
from damage due to high temperatures, which can occur under severe operating conditions. By altering shift sched-
ules, line pressure, and converter clutch control, these controls reduce heat generation and increase transmission
cooling.

To help reduce efficiency-robbing parasitic losses, the transmissions includes a dual-stage transmission fluid pump
with electronic output pressure control. Under most driving conditions, pump output capacity greatly exceeds that
which is needed to keep the clutches applied. The 45RFE/545RFE pump-pressure control system monitors input
torque and adjusts the pump pressure accordingly. The primary stage of the pump works continuously; the second
stage is bypassed when demand is low. The control system also monitors input and output speed and, if incipient
clutch slip is observed, the pressure control solenoid duty cycle is varied, increasing pressure in proportion to
demand.

A high-travel torque converter damper assembly allows earlier torque converter clutch engagement to reduce slip-
page. Needle-type thrust bearings reduce internal friction. The 45RFE/545RFE is packaged in a one-piece die-cast
aluminum case. To reduce NVH, the case has high lateral, vertical and torsional stiffness. It is also designed to
maximize the benefit of the structural dust cover that connects the bottom of the bell housing to the engine bed-
plate, enhancing overall power train stiffness. Dual filters protect the pump and other components. A cooler return
filter is added to the customary main sump filter. Independent lubrication and cooler circuits assure ample pressure
for normal transmission operation even if the cooler is obstructed or the fluid cannot flow due to extremely low
temperatures.

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AUTOMATIC TRANSMISSION 545RFE - SERVICE INFORMATION

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