Transmission Speed Sensor - Input

Replace the input speed sensor on the 47RE/48RE automatic transmission, typically located on the driver's side of the transmission case.

Warnings

Tools required

Parts

• Input speed sensor (transmission) × 1 — Mopar 5017119AA or equivalent
• Sensor O-ring (if not included with sensor) × 1 — Use OEM specification

Fluids

• Mopar ATF+4 — 1.5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow transmission to cool to safe working temperature if recently driven
3. Raise and safely support vehicle on lift or jack stands with sufficient clearance to access underside of transmission
4. Locate the input speed sensor on the driver's side of the transmission case, forward of the pan
5. Clean the area around the sensor with shop towels to prevent contamination

Procedure

1. 1

   Disconnect sensor electrical connector
   Locate the wiring harness connector attached to the input speed sensor. Press the locking tab and carefully pull the connector straight off the sensor. Inspect the connector pins for corrosion or damage. Verify correct Mopar part number against manufacturer documentation for the specific transmission (47RH/47RE/48RE).
2. 2

   Position drain pan
   Place a drain pan directly below the input speed sensor location. Depending on sensor position relative to fluid level, some ATF+4 may drain from the opening — typically only a small amount unless the bore is below fluid level.
3. 3

   Remove sensor mounting bolt
   Using the appropriate socket, remove the bolt(s) or retainer securing the input speed sensor to the transmission case. Verify sensor retention method and fastener size against service documentation. Keep the bolt for inspection and potential reuse.
4. 4

   Extract the sensor
   Carefully pull the sensor straight out of the transmission case bore. Fluid will begin draining immediately. Allow fluid to drain into the pan until flow reduces to a slow drip. Inspect the old sensor for metal debris on the magnetic tip, which may indicate internal transmission wear.
5. 5

   Clean the sensor bore
   Use a clean shop towel to wipe the sensor bore opening in the transmission case. Remove any debris or old O-ring material. If available, use a wire brush to clean the mounting surface around the bore, then wipe clean again.
6. 6

   Prepare new sensor
   Remove the new input speed sensor from packaging. Verify the O-ring is properly seated in the sensor groove. If the O-ring is separate, install it onto the sensor body. Lightly lubricate the O-ring with clean ATF+4 to ease installation and prevent damage.
7. 7

   Install new sensor
   Carefully insert the new sensor straight into the transmission case bore, ensuring the O-ring does not roll or pinch. Push the sensor in until it seats fully against the case. Align the mounting hole with the threaded bore in the case.
8. 8

   Torque sensor mounting bolt
   Install the sensor mounting bolt and hand-tighten. Using a torque wrench, tighten the bolt to specification in a smooth, steady motion. Verify the torque value against Mopar service documentation, as no specific torque value is provided in this procedure and the referenced specification must be confirmed against Mopar service data. Do not overtighten, as this can crack the sensor body or strip the aluminum case threads.
9. 9

   Reconnect electrical connector
   Push the wiring harness connector onto the new sensor until it clicks into place. Verify the locking tab is fully engaged. Gently tug on the connector to confirm it is secure.
10. 10

    Refill transmission fluid
    Locate the transmission dipstick tube. Using a funnel and fluid pump, add Mopar ATF+4 through the dipstick tube to replace only the volume of fluid lost during service. Add fluid slowly and check the dipstick frequently to avoid overfilling.
11. 11

    Check fluid level
    With the engine running, transmission in Park, and vehicle on level ground, allow transmission to reach operating temperature (approximately 180°F). Check the fluid level on the dipstick at the HOT mark. Add fluid as necessary to bring level to the correct range. Do not overfill. Check for diagnostic trouble codes related to the input/turbine speed sensor (P0715, P0716, P0717) - codes should be absent. NOTE: 1994-1995 models are pre-OBD2 and require a Chrysler DRB-style scan tool for codes.

Reassembly

1. Ensure sensor mounting bolt is torqued to specification and electrical connector is fully seated
2. Verify no fluid leaks are present around the sensor after refilling
3. Remove all tools and drain pan from under vehicle before lowering

Verification

• Start the engine and verify no transmission fluid leaks around the input speed sensor
• Using a scan tool, verify the input speed sensor is reading properly (should show 0 RPM in Park, and register speed when vehicle is moved)
• Test drive the vehicle and confirm speedometer operates correctly and transmission shifts normally through all gears
• Check for diagnostic trouble codes related to input speed sensor (P0715, P0717, P0720) - codes should be absent
• Recheck transmission fluid level after test drive and top off if necessary

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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