P0979
Shift Solenoid C Control Circuit Low
Transmission control
Generic OBD-II
Medium
What it means
P0979 means the control circuit for shift solenoid C is reading low voltage, usually a short to ground or a failed solenoid. The transmission may not shift into the affected gear, shift harshly, or drop into limp mode. Start by checking the solenoid connector and wiring for a ground short before condemning the solenoid or the control module.
Medium
Can I keep driving? Driveable but expect shifting problems — the transmission may hold a gear or enter limp mode, so repair it before the fault worsens.
Common symptoms
What you'll notice
- Check-engine light on
- May not shift into the gear controlled by solenoid C
- Harsh or delayed shifting
- Reduced acceleration or power
- Possible limp (fail-safe) mode
Common causes
Most likely first
- Shift solenoid C shorted or faulty (low-side control circuit)Likely
- Wiring shorted to ground in the solenoid circuitCommon
- Corroded or damaged connectorCommon
- Faulty transmission control module (TCM)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm which gear/shift is affected.
- Inspect the solenoid connector and wiring for a short to ground or damage.
- Measure shift solenoid C resistance and compare to spec; replace if shorted.
- Repair any chafed or grounded wiring found.
- If solenoid and wiring are good, have the TCM tested and replaced as a last resort.
FAQ
Quick answers
Is it safe to drive with P0979?+
Short trips are usually okay, but the transmission may not shift normally or may go into limp mode, which limits speed. Repair it soon.
Can I just clear P0979?+
It will return until the shorted solenoid or wiring is repaired. Clearing it does not restore the shift function.
Related codes
Often seen with P0979
Read & clear P0979 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX