1. Low Transmission
Transmission fluid not only lubricates
and helps cool the internal workings of the transmission, it also
provides the pressure needed to shift gears. Thus, when the
fluid level is low, the transmission may slip, shift hard, shift
erratically or not shift at all. Gear engagement may be
delayed. Low fluid also causes the transmission or transaxle
the correct type of transmission fluid until the fluid level on the
dipstick shows in the "full range". How to properly check
transmission fluid level
$5 to $10
per quart of ATF.
and dirty transmission fluid can cause many of the same symptoms as
having low fluid. Additionally, dirty fluid can clog the
filter, which will cause even more shift problems as the fluid pressure
needed to make shifts is insufficient. With a clogged filter,
the transmission oil pump must work double hard to pump fluid through
the transmission and thus is more likely to fail.
filter change or fluid flush.
Cost: DIY Cost: $40 to $95. Shop
Cost : $110 to $350+
3. Oxidized "burnt"
Burnt/oxidized transmission fluid may
mean some internal transmission damage has already occurred.
But, whether it is time for a rebuild is still questionable.
Solution: The recommended action
is to change the fluid and filter or possibly a fluid flush depending
on the vehicle mileage and whether the transmission has been flushed
previously. If changing the fluid and filter (or flushing the
transmission) does not resolve the problem(s) you are experiencing, a
rebuild may be needed.
Costs for cost
4. Faulty shift Solenoid
- Open Electrical Circuit: A failed shift solenoid or an
open/shorted electrical connection can cause delayed and erratic shift
or no shifts. The condition may cause the vehicle to jerk
when placing the shifter level into "Drive" or "Reverse" and when the
transmissions shifts automatically.
If the check engine light is illuminated, an OBDII scan may provide
information pointing to the problem solenoid. If the check
engine light is not illuminated, pinpointing a faulty transmission
solenoid or locating an open electrical problem will require a series
of electrical tests or a scan of the vehicle's powertrain using a
special transmission scanner. Transmission repair shops have
the equipment and special scanners needed to find open circuits and
other electrical problems.
Do-it-yourself cost: $40 for a single solenoid to $250 or more for a
solenoid pack. The transmission oil pan must be removed to
access the shift solenoids. Repair shop cost range: $175 to
5. Failed Sensor(s)
and/or Switches: Today's automatic
transmissions and transaxles are controlled by an electrical (computer)
device called a Transmission Control Module "TCM". Note: Some
vehicles use a Powertrain Control Module "PCM" for both the engine and
The TCM (or PCM) relies on
input data received from various switches and sensors to control the
operation of the transmission. These sensors and switches include the
throttle position sensor, crankshaft position sensor, wheel speed
sensors, ATF temperature sensor, brake switch, inhibitor switch, torque
converter turbine speed sensor and others. The failure of
anyone of these sensors or switches can cause a number of different
transmission problems, including shift problems.
If the check engine light is
illuminated, an OBD-II scan should identify the faulty sensor or
solenoid. If check engine light is not illuminated, a
transmission scan may be necessary. Transmission repair shops
are typically the only auto repair shops that have these special
Do-it-yourself cost: The cost range for sensors and switches is $25 to
$200+. Repair shop cost: $125 to $350+.
6. Valve Body Problem:
transmission valve body controls shifts by controlling fluid pressure
and directing transmission fluid into the appropriate passageways to
initiate and activate gear shifts. Over time, metal debris
can scratch or score the aluminum passages of the valve body causing a
change in pressure, which can cause numerous shift problems including
hard "jerky" shifts and delayed shifts. If any of the valve
body passages become blocked by debris, the transmission may not shift
into the appropriate gear, either automatically or by manually shifting.
Replace valve body. The
valve body can be replaced without removing the transmission.
Do-it-yourself cost: $300 - $1,000 for
the cost of a new valve body. Repair shop labor for replacing
the valve body is $150 to $350.
7. Worn, Frayed, or
Broken Shifter Cable:
Over time, the shifter cable can become worn, frayed or even
break. Oftentimes, a worn or frayed shifter cable will cause
the transmission to be in a different gear than the shifter indicator
shows. For example, the shifter lever can be in the Park
position but the transmission can be in Reverse or Neutral.
When this happens, the engine may not crank when turning the key to
start the vehicle because the transmission is not in Park even though
the shifter lever indicates it is. With a broken shifter
cable, the transmission cannot be shifted into any gear.
Replace shifter cable.
cost: $50 to $150 for the cost of cable. Repair shop cost:
$150 to $275.
Shifter Linkage: The symptoms of a shifter
linkage being out-of-adjustment are similar to a worn or frayed shifter
cable. The difference is that with a worn shifter cable you
may feel a looseness in the shifter level when moving the shifter
lever. With an out-of-adjustment linkage you will probably
not feel any difference in the shifter lever movement. A
shifter linkage out-of-adjustment can also cause the transmission to be
in a different gear than what the shifter lever shows.
Adjust shifter linkage
Do-it-yourself cost $0. Repair shop cost: $50 to $75.
9. Faulty Transmission
Control Module (TCM) or Powertrain Control Module (PCM):
A faulty Transmission Control Module
(TCM) or Powertrain Control Module (PCM) can cause erratic shifts, hard
shifts, delays between gear shifts, hard downshifts and taking longer
than normal to go into Reverse or Drive. The transmission may
fail to engage in any gear.
Test TCM (or PCM) and replace if found
to be faulty.
Cost: Diagnosing a faulty TCM or PCM may
require a professional transmission scan to be performed. The
cost range for this type of scan is $50 to $125. The cost for
a new TCM or PCM can range from from $75 for a used module to $500 or more new module.
Many of the
above conditions will cause the transmission "Drive" indicator light to
illuminate or flash. The transmission may then go into "Limp
Mode" (also called "Safe Mode" or "Fail Safe". When this
happens, the transmission will become locked in either 2nd or 3rd gear
in order to protect the transmission from internal damage.
When in Limp Mode, drive slowly and directly to a repair shop or to
your destination and park the vehicle until it can be checked-out by a
professional. Continuing to drive a vehicle when the
transmission is in limp mode can ruin the transmission.
agreeing to a rebuild, get an estimate for a remanufactured
transmission. You may get a better price/warranty on a reman vs. a
rebuild. Get an estimate via e-mail within hours using the button below:
an Estimate online