P0787 Shift/Timing Solenoid Low

The Diagnostic Trouble Code (DTC) P0787, indicating a Shift/Timing Solenoid Low issue, points to potential concerns within a vehicle’s transmission system. This comprehensive guide aims to clarify the meaning behind the P0787 code, explore its possible causes, outline associated symptoms, and detail diagnostic procedures and repair methods linked to this specific OBD2 trouble code.

1. What Does P0787 Code Mean?

P0787 specifically denotes a low signal or performance problem related to the transmission’s shift or timing solenoid, as detected by the Powertrain Control Module (PCM). This code highlights an issue concerning the solenoid’s operation responsible for controlling gear timing or shifting, affecting the transmission’s performance.

2. What Are The Possible Causes Of P0787 OBD2 Trouble Code?

Several factors might trigger the activation of P0787, including:

  • Faulty Solenoid: Issues with the operation or performance of the shift/timing solenoid.
  • Transmission Fluid Problems: Inadequate, contaminated, or deteriorated transmission fluid impacting solenoid functionality.
  • Wiring or Connector Issues: Damaged, loose, or corroded electrical connections affecting solenoid control signals.
  • Mechanical Concerns: Internal mechanical irregularities within the transmission impacting solenoid performance.
  • PCM Dysfunction: Problems within the Powertrain Control Module influencing solenoid operations.

3. What Are The Symptoms Of OBD2 Trouble Code P0787?

When the P0787 code is active, several symptoms might become noticeable, including:

  • Check Engine Light Activation: Illumination of the check engine light indicating transmission irregularities.
  • Harsh Shifting: Abrupt or rough shifting patterns during gear transitions.
  • Transmission Slippage: Unusual slipping or hesitation during gear shifts.
  • Reduced Performance: Impaired transmission performance affecting vehicle acceleration and efficiency.

4. How To Diagnose And Repair Problems That Activated DTC P0787 in The PCM?

For an accurate diagnosis and repair approach concerning DTC P0787:

  • OBD-II Scan: Use a diagnostic scanner to retrieve the P0787 code and accompanying codes for comprehensive analysis.
  • Transmission Fluid Inspection: Check transmission fluid levels, quality, and condition as per manufacturer specifications.
  • Wiring and Solenoid Examination: Inspect wiring and connectors associated with the shift/timing solenoid for damage, loose connections, or corrosion.
  • Mechanical Assessment: Conduct a detailed inspection of the transmission system for mechanical issues impacting solenoid performance.
  • PCM Evaluation: Assess the Powertrain Control Module for potential malfunctions influencing solenoid operations.


Understanding the implications of DTC P0787 facilitates a systematic approach to diagnose and rectify issues within the transmission’s shift or timing solenoid low signal/performance. Awareness of its causes, symptoms, and diagnostic and repair processes empowers efficient resolution, ensuring smooth gear transitions within the vehicle.

Consulting certified auto technicians or professionals experienced in transmission repairs is advisable for precise diagnosis and resolution of issues associated with DTC P0787. Timely maintenance and professional guidance significantly contribute to maintaining optimal transmission performance and overall vehicle reliability.