PT Cruiser, 2001 - 2005

Output Speed Sensor (OSS)

Print

Description & Operation



The Output Speed Sensor is a two-wire magnetic pickup device that generates an AC signal as rotation occurs. It is threaded into the transaxle case, sealed with an O-ring, and is considered a primary input to the Transmission Control Module (TCM)

The Output Speed Sensor provides information on how fast the output shaft is rotating. As the rear planetary carrier park pawl lugs pass by the sensor coil, an AC voltage is generated and sent to the TCM. The TCM interprets this information as output shaft rpm

The TCM compares the input and output speed signals to determine the following:



Transmission gear ratio
 
Speed ratio error detection
 
CVI calculation
 

Vehicle Speed Signal

The vehicle speed signal is taken from the Output Speed Sensor. The TCM converts this signal into a pulse per mile signal and sends it to the PCM. The PCM, in turn, sends the vehicle speed message across the communication bus to the BCM. The BCM sends this signal to the Instrument Cluster to display vehicle speed to the driver. The vehicle speed signal pulse is roughly 8000 pulses per mile.

Click image to see an enlarged view

Fig.

Removal & Installation




WARNING
When disconnecting speed sensor connector, be sure that the connector weather seal does not fall off or remain in old sensor.

  1. Disconnect the battery cables.
  2.  
  3. Remove air cleaner assembly.
  4.  
  5. Remove the battery hold down clamp and remove the battery.
  6.  
  7. Remove the battery tray.
  8.  
  9. Disconnect output speed sensor connector.
  10.  
  11. Unscrew and remove output speed sensor.
  12.  
  13. Inspect speed sensor O-ring and replace if necessary.
  14.  

To install:

  1. Verify O-ring is installed into position.
  2.  
  3. Install and tighten output speed sensor to 27 Nm (20 ft. lbs.)
  4.  
  5. Connect speed sensor connector.
  6.  
  7. Install the battery tray.
  8.  
  9. Install the battery and hold down clamp.
  10.  
  11. Install air cleaner assembly.
  12.  

 
label.common.footer.alt.autozoneLogo