WOMS
P code powertrain High severity

P1755 Intermediate Speed Sensor (ISS) Malfunction

The OBD2 code P1755 indicates a malfunction in the Intermediate Speed Sensor (ISS), which is responsible for monitoring the transmission's intermediate speed and providing data to the engine control module for proper...

Definition

The OBD2 code P1755 indicates a malfunction in the Intermediate Speed Sensor (ISS), which is responsible for monitoring the transmission's intermediate speed and providing data to the engine control module for proper shifting and performance

Common causes

  • Faulty Intermediate Speed Sensor (ISS)
  • Wiring issues or damaged connectors
  • Poor electrical connections
  • Transmission fluid issues (low level or contamination)
  • Faulty transmission control module (TCM)
  • Mechanical issues within the transmission
  • Software glitches in the vehicle's computer system

Common misdiagnoses

  • Transmission fluid issues
  • Faulty transmission control module (TCM)
  • Speed sensor issues (other than ISS)
  • Wiring or connector problems
  • Torque converter issues
  • Engine control module (ECM) faults
  • Mechanical transmission problems
  • Incorrectly diagnosed transmission slipping or shifting issues

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue

  2. 2. Inspect Wiring and Connectors

    Visually inspect the wiring and connectors associated with the ISS. Look for signs of damage, corrosion, or loose connections. Pay special attention to the harness leading to the sensor

  3. 3. Test the Intermediate Speed Sensor

    If accessible, test the ISS using a multimeter. Check for proper resistance and voltage output according to the manufacturer’s specifications. If the sensor is faulty, it may need to be replaced

  4. 4. Check the Transmission Fluid

    Low or dirty transmission fluid can affect sensor performance. Check the fluid level and condition. If the fluid is dirty or burnt, consider changing it

  5. 5. Inspect the Transmission Control Module (TCM)

    Ensure that the TCM is functioning properly. A malfunctioning TCM can lead to incorrect readings from the ISS. Check for any software updates or reprogramming that may be needed

  6. 6. Look for Mechanical Issues

    Inspect the transmission for any mechanical issues that could affect the ISS, such as worn gears or internal damage

  7. 7. Perform a Visual Inspection of the Transmission

    Check for any signs of leaks or damage to the transmission housing that could affect sensor operation

  8. 8. Clear the Codes and Test Drive

    After performing any repairs or adjustments, clear the trouble codes and take the vehicle for a test drive to see if the code returns

  9. 9. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the ISS or transmission issues for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues

  10. 10. Seek Professional Help

    If the issue persists after performing these steps, it may be best to consult a professional mechanic or technician who has experience with transmission issues and OBD-II diagnostics.Conclusion By following these troubleshooting steps, you can systematically identify and address the cause of the P1755 code. Always refer to the vehicle’s service manual for specific procedures and specifications related to your particular make and model