P0979 Fault Code

Shift Solenoid C Control Circuit Low

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0979 fault code indicates an issue with the Shift Solenoid C Control Circuit, specifically a condition of low voltage or improper signal. This code is often related to automatic transmission functioning and is crucial for proper gear shifting. When the control circuit experiences low voltage, it may lead to delayed or harsh shifting, impacting the overall performance of the vehicle.

What are the symptoms of the P0979 code?

Drivers may experience a variety of symptoms when the P0979 code appears, including:

• Sluggish or unresponsive shifting between gears
• Noticeable delays in gear engagement
• Harsh or abrupt gear changes
• Transmission feels as though it is slipping
• Illuminated check engine light on the dashboard

What causes the P0979 code?

The low voltage in the Shift Solenoid C Control Circuit could be caused by several factors, including:

• A faulty shift solenoid C
• Damaged wiring or connectors in the circuit
• Low transmission fluid levels or poor fluid condition
• Issues with the transmission control module (TCM)
• Corrosion or shorts in the electrical connections

How to fix P0979?

To resolve the P0979 fault code, consider the following corrective actions:

• Inspect the shift solenoid C for proper operation and replace if necessary.
• Check wiring and connectors in the control circuit for damage, corrosion, or loose connections.
• Ensure transmission fluid is at the correct level and in good condition; replace if needed.
• Perform a diagnostic scan to rule out issues with the transmission control module and reprogram or replace it as required.
• Clear the fault code and test drive the vehicle to see if the issue reoccurs.