P0979
Shift Solenoid "C" Control Circuit Low
DTC P0979, sometimes indicated as P097900 is an OBD diagnostic trouble code indicating a generic fault with the vehicle powertrain (i.e. engine and gearbox). This code identifies an error with the transmission (gearbox) causing shift solenoid "c" control circuit low.
The "Shift Solenoid C" control circuit low input is a message from the Powertrain Control Module (PCM) that there is a problem with the solenoid circuit that controls the gearshift. This can be caused by a number of things, including a faulty solenoid, a wiring problem, or a problem with the PCM.
If you are experiencing this code, the first thing to do is to check the wiring and connectors for the shift solenoid. If everything looks OK, then you will need to test the solenoid itself. You can do this using a voltmeter or a scan tool. If the solenoid is bad, then you will need to replace it.
- P0979: Shift Solenoid "C" Control Circuit Low
- P0979: Shift Solenoid C Control Circuit Low
- P0979: Shift solenoid (SS) C – circuit low
- P0979 00: Shift solenoid (SS) C - circuit low
2011 FORD F-150 with 89000.0 miles
On 12 january 2017 when returning from a normal oil change and tire rotation at a dealership the operator heard what sounded like marbles in a coffee can coming from the transmission and the vehicle experienced erratic shifts and loss of power. These conditions were reported to and noted by the dealership's receptionist to be followed up on the next morning. On 13 january 2017 on the commute to work when accelerating from a stoplight on a city thoroughfare the vehicle downshifted abruptly from a high gear and shuddered to a halt in the middle of the roadway. The incident was so dramatic that the operator had assumed the driveshaft had been lost. The operator limped the vehicle into a nearby parking lot where the dashboard showed various warnings (see exhibit 1) and a towing company was called to transport the vehicle to the dealership. The vehicle had approximately 89,000 miles and the weather was sunny and 42 f on 13 january 2017. The dealership diagnosed the issue as an internal failure by using codes P0763, P0764, and P0979, along with removing the transmission pan which showed fine metallic shavings (see exhibit 2); the transmission was replaced by the dealership. This transmission issue was fortunate to not have resulted in any injuries or additional damages which could have easily occurred.
POWER TRAIN,