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P078D Severity
Identifying an OBD code is just the start of a complete diagnostic routine. Most trouble codes are caused by a sensor reporting a value that is out of range. Just replacing a sensor may not fix underlying issues. Be sure to understand the code, the part or system in your car that the code refers to, and the risks of delaying professional repair.
Proper diagnosis will save you time and money on unnecessary repairs.
Urgent codes indicate immediate action is necessary. These are urgent and significant malfunctions that can cause severe damage to the vehicle or harm the driver and passengers.
The Transmission Control Module (TCM) uses shift solenoids to control the hydraulic pressure in the transmission which is needed to apply the various clutch packs in the transmission that provide the different gear ratios needed to efficiently propel the vehicle down the roadways. When the TCM detects a shift solenoid is not performing as desired, it will set code P078D.
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OBD-II Code Transmission may not shift properly is defined as a Shift Timing Solenoid "B" High
The Transmission Control Module (TCM) uses shift solenoids to control the hydraulic pressure in the transmission which is needed to apply the various clutch packs in the transmission that provide the different gear ratios needed to efficiently propel the vehicle down the roadways. When the TCM detects a shift solenoid is not performing as desired, it will set code P078D.