Error code
OBD2 P0978
OBD2P0978
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.
What it means
Shift Solenoid 'C' Control Circuit Range/Performance.
Severity
moderateCan drive but may experience transmission performance issues.
Summary
P0978 indicates an issue with Shift Solenoid C in the transmission control system, affecting its performance and range.
Symptoms
- Check Engine light is on
- Sluggish acceleration or high revving
- Noticeable harsh shifts
Common Causes
- Shift solenoid failure
- Wiring issues (poor connection, corrosion, moisture)
- Transmission Control Module (TCM) or Engine Control Module (ECM) malfunction
Diagnosis
- Inspect wiring harness for breaks, corrosion, and poor connections
- Check continuity at the TCM harness using a digital volt-ohm meter (DVOM)
- Test Shift Solenoid C's resistance with specifications from your vehicle manual
- Exchange control module if necessary
Fixes
- Replace faulty shift solenoid or wiring harness
FAQ
What should I do if the Check Engine light comes on with P0978?
Inspect and repair any wiring issues, test Shift Solenoid C's resistance, and consider replacing faulty components.
Can I drive my car with this code?
You can drive but may experience transmission performance issues such as sluggish acceleration or harsh shifts.
Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
More OBD2 codes
- P0900Clutch Actuator Circuit/Open
- P0901Clutch Actuator Circuit Range/Performance
- P0902Clutch Actuator Circuit Low
- P0903Clutch Actuator Circuit High
- P0904Gate Select Position Circuit
- P0905Gate Select Position Circuit Range/Performance
- P0906Gate Select Position Circuit Low
- P0907Gate Select Position Circuit High
- P0908Gate Select Position Circuit Intermittent
- P0909Gate Select Control Error
- P0910Gate Select Actuator Circuit/Open
- P0911Gate Select Actuator Circuit Range/Performance