DTC P1840: CVT Speed Sensor Circuit Forward Rotation Range/Performance

NOTE: 

• Before you troubleshoot, review the General Troubleshooting Information - Refer to: How to Troubleshoot the Fuel and Emissions SystemsHow to Troubleshoot the CVT System(CVT System) .
• This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

DTC (CVT)

• 1. CVT speed sensor check:

  - 1. Turn the vehicle to the ON mode.

  - 2. Clear the DTC with the HDS.

  - 3. Raise the vehicle on a lift. Make sure it is securely supported, and allow the front wheels to rotate freely.

  - 4. Start the engine.

  - 5. Disable the VSA by pressing the VSA OFF button.

  - 6. Test-drive the vehicle in D position/mode, while monitoring the Direction of Secondary-shaft Rotation in the Data List with the HDS.

  - 7. Check the parameter below with the HDS.

  Signal	Current conditions
  	Values	Unit
  Direction of Secondary-shaft Rotation

  Does the HDS indicate forward?

  YES 

  The CVT speed sensor is OK. Update the PCM if it does not have the latest software , or substitute a known-good PCM , then recheck. If DTC P1840 goes away and the PCM was updated, troubleshooting is complete. If DTC P1840 goes away and the PCM was substituted, replace the original PCM .

  NO 

  Faulty the CVT speed sensor. Replace the CVT speed sensor .