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P code powertrain Medium severity

P1307 Kickdown Relay Hold Circuit Fault

The OBD2 code P1307 indicates a fault in the kickdown relay hold circuit, which affects the transmission's ability to downshift properly during acceleration

Definition

The OBD2 code P1307 indicates a fault in the kickdown relay hold circuit, which affects the transmission's ability to downshift properly during acceleration

Common causes

  • Faulty kickdown relay
  • Wiring issues (shorts or open circuits)
  • Poor connections or corroded terminals
  • Malfunctioning transmission control module (TCM)
  • Faulty throttle position sensor (TPS)
  • Issues with the engine control module (ECM)
  • Problems with the vehicle's power supply or ground connections

Common misdiagnoses

  • Faulty kickdown relay
  • Wiring issues or shorts in the circuit
  • Faulty transmission control module (TCM)
  • Incorrectly diagnosed transmission problems
  • Faulty throttle position sensor (TPS)
  • Engine control module (ECM) issues
  • Misinterpretation of other related codes
  • Problems with the accelerator pedal position sensor

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Addressing any related codes can help in diagnosing the issue more effectively

  2. 2. Inspect the Kickdown Relay

    Locate the kickdown relay in the vehicle's fuse box or relay panel. Check for any signs of damage, corrosion, or poor connections. If the relay appears faulty, consider replacing it

  3. 3. Test the Relay

    If you have access to a multimeter, you can test the relay for proper operation. Check for continuity and ensure that it activates when the appropriate voltage is applied

  4. 4. Check Wiring and Connectors

    Inspect the wiring and connectors associated with the kickdown relay and the transmission control module. Look for frayed wires, loose connections, or corrosion that could affect the circuit

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

    The TCM may be malfunctioning or have a poor connection. Check for any signs of damage or corrosion on the TCM connectors. If necessary, test the TCM for proper operation

  6. 6. Check for Ground Issues

    Ensure that the kickdown relay and TCM have a good ground connection. A poor ground can lead to erratic behavior and trigger fault codes

  7. 7. Examine the Throttle Position Sensor (TPS)

    The TPS provides input to the TCM regarding the position of the throttle. If the TPS is malfunctioning, it may cause issues with the kickdown function. Test the TPS for proper operation and replace it if necessary

  8. 8. Inspect the Transmission Fluid

    Low or dirty transmission fluid can affect transmission performance. Check the fluid level and condition, and change it if necessary

  9. 9. Clear the Code and Test Drive

    After performing the necessary repairs, clear the trouble code using the OBD-II scanner. Take the vehicle for a test drive to see if the code returns

  10. 10. Consult a Professional

    If the issue persists after performing these steps, it may be best to consult a professional mechanic or technician who has experience with transmission systems and can perform more in-depth diagnostics. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P1307 code