WOMS
P code powertrain Medium severity

P1907 Kickdown Hold Relay Open or Short Circuit to Ground

The OBD2 code P1907 indicates a malfunction in the kickdown hold relay, either due to an open circuit or a short circuit to ground, affecting the transmission's ability to shift properly during acceleration

Definition

The OBD2 code P1907 indicates a malfunction in the kickdown hold relay, either due to an open circuit or a short circuit to ground, affecting the transmission's ability to shift properly during acceleration

Common causes

  • Faulty kickdown hold relay
  • Damaged wiring or connectors
  • Short circuit in the wiring harness
  • Open circuit in the wiring
  • Faulty transmission control module (TCM)
  • Malfunctioning throttle position sensor (TPS)
  • Issues with the vehicle's powertrain control module (PCM)

Common misdiagnoses

  • Transmission control module (TCM) failure
  • Faulty kickdown switch
  • Wiring issues or shorts in the harness
  • Faulty transmission solenoids
  • Incorrectly diagnosed transmission fluid issues
  • Malfunctioning throttle position sensor
  • Engine control module (ECM) problems
  • Misinterpretation of other transmission codes
  • Faulty connectors or terminals
  • Issues with the vehicle's battery or charging system

Troubleshooting steps

  1. 1. Check the OBD-II Codes:

    Use an OBD-II scanner to confirm the P1907 code and check for any additional codes that may provide more context about the issue

  2. 2. Inspect the Kickdown Hold Relay:

    Locate the kickdown hold relay in the vehicle's fuse box or relay panel

  3. 3. Check the relay for any visible signs of damage, corrosion, or burnt contacts

  4. 4. If necessary, swap the relay with a similar one (if available) to see if the problem persists

  5. 5. Examine Wiring and Connectors:

    Inspect the wiring harness and connectors associated with the kickdown hold relay for any signs of wear, fraying, or damage

  6. 6. Look for loose connections, corrosion, or broken wires that could cause an open circuit or short to ground

  7. 7. Test the Relay Circuit:

    Use a multimeter to test the relay circuit for continuity. Check for an open circuit by measuring resistance across the relay terminals

  8. 8. Check for proper voltage at the relay terminals when the ignition is on and the vehicle is in the appropriate gear

  9. 9. Check for Short Circuits:

    With the multimeter, check for continuity between the relay circuit and ground. If there is continuity, it indicates a short circuit to ground

  10. 10. Inspect the wiring for any points where it may be pinched or damaged, causing a short

  11. 11. Inspect the Transmission Control Module (TCM):

    If the relay and wiring appear to be in good condition, the issue may lie within the Transmission Control Module (TCM)

  12. 12. Check for any software updates or known issues with the TCM for your specific vehicle model

  13. 13. Clear Codes and Test Drive:

    After performing repairs, clear the OBD-II codes using the scanner

  14. 14. Take the vehicle for a test drive to see if the code reappears. Monitor the transmission's performance during the drive

  15. 15. Consult a Professional:

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with transmission systems and electrical diagnostics.Additional Tips: - Always refer to the vehicle's service manual for specific wiring diagrams and relay locations. - Ensure that the vehicle's battery is in good condition, as electrical issues can sometimes stem from a weak battery. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P1907 code