P0978: Shift Solenoid “C” Control Circuit Range/Performance OBD-II Trouble Code

Each shift solenoid is responsible for controlling different clutches and gears. If a particular shift solenoid is not performing the way it has been programmed to do, then a P0978 DTC will be saved.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

How Serious is the Code?

Although the severity of a P0978 diagnostic trouble code may not seem too bad at first, the transmission problems will get a lot worse. Eventually leading to a transmission that will not shift into different gears.

Symptoms

Symptoms of a P0978 include:

  • Harsh shifts
  • Transmission may not shift into gear

Causes

  • Low transmission fluid
  • Dirty transmission fluid/filter
  • Damaged wiring and/or corroded or broken connectors
  • Shift solenoid malfunction

How to Diagnose the Code?

Transmission fluid is very important to the operation of a shift solenoid. Believe it or not, dirty or low transmission fluid can actually cause a P0978 OBDII trouble code, so that should be the first thing that is checked. Damaged wiring or broken connectors along the transmission wiring harness can also cause this OBD2 code. If no issues are found in either of these areas, then the shift solenoid C should be checked.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

What Repairs Will Fix P0978?

  • Service the transmission
  • Replace or repair damage wiring/connectors
  • Replace shift solenoid

Related Codes

  • P0979 – Shift Solenoid “C” Control Circuit Low
  • P0980 – Shift Solenoid “C” Control Circuit High