DTC P0803 1-4 Upshift (Skip Shift) Solenoid Control Circuit Malfunction

The Diagnostic Trouble Code (DTC) P0803 relates to the 1-4 Upshift (Skip Shift) Solenoid Control Circuit within the vehicle’s transmission system. This guide aims to elucidate the significance of the P0803 code, explore potential causes, outline associated symptoms, and provide guidance on diagnosing and rectifying issues linked to this specific OBD2 trouble code.

1. What Does P0803 Code Mean?

P0803 specifically indicates a malfunction within the control circuit responsible for the 1-4 upshift solenoid, also known as the skip shift solenoid. It signifies an irregularity or fault detected by the vehicle’s Powertrain Control Module (PCM) in this particular circuit.

2. What Are The Possible Causes Of P0803 OBD2 Trouble Code?

Several factors could trigger the activation of P0803, including:

  • Faulty Upshift Solenoid: Malfunction or failure of the 1-4 upshift (skip shift) solenoid itself.
  • Electrical Issues: Wiring problems, damaged connectors, or corrosion affecting the integrity of the control circuit.
  • Faulty Solenoid Control Circuit: Issues within the circuit controlling the 1-4 upshift solenoid.
  • Transmission Control Module (TCM) Malfunction: Anomalies or intermittent problems within the Transmission Control Module impacting the solenoid control circuit.

3. What Are The Symptoms Of OBD2 Trouble Code P0803?

When DTC P0803 is active, various symptoms may manifest, including:

  • Check Engine Light Activation: Illumination of the check engine light due to detected abnormalities in the 1-4 upshift solenoid control circuit.
  • Transmission Shifting Issues: Irregular or hesitant shifting between gears, particularly during the 1-4 upshift sequence.
  • Decreased Fuel Efficiency: Potential decrease in fuel efficiency due to improper shifting patterns.

4. How To Diagnose And Repair Problems That Activated DTC P0803 in The PCM?

Accurate diagnosis and repair concerning DTC P0803 involve:

  • OBD-II Scan: Use a diagnostic scanner to retrieve the P0803 code and any associated codes for comprehensive diagnosis.
  • Visual Inspection: Inspect wiring, connectors, and the solenoid for visible damage, corrosion, or loose connections.
  • Circuit Testing: Utilize a multimeter to test the 1-4 upshift solenoid control circuit for continuity, shorts, or open circuits to ensure proper functionality.
  • Solenoid Assessment: Check the 1-4 upshift solenoid and related components for defects or irregularities impacting circuit operation.
  • TCM Evaluation: Evaluate the Transmission Control Module for possible malfunctions affecting the solenoid control circuit.


Understanding DTC P0803 signifies issues within the 1-4 Upshift (Skip Shift) Solenoid Control Circuit, impacting the transmission’s ability to execute the 1-4 upshift sequence correctly. Thorough diagnosis, including visual inspections, circuit testing, and component assessments, is crucial for resolving this malfunction and ensuring the transmission system operates optimally.

Consulting certified auto technicians or professionals experienced in transmission repairs is advisable for precise diagnosis and resolution of issues associated with DTC P0803. Timely maintenance and professional guidance significantly contribute to maintaining optimal transmission performance and overall vehicle reliability.