P077A
Output Speed Sensor Circuit - Loss of Direction Signal
Generic code
Transmission System
High severity
Hard repair
Free on OBD DashX
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What P077A means
- Gear system is not able to read engine RPM output correctly
Possible symptoms
- Four-wheel drive may not engage
- Possible shifting problems
Possible causes
- Problems with the electric wiring or connections
- A malfunctioning transmission fluid temperature sensor
- A malfunctioning output shaft speed sensor
- A malfunctioning speed sensor
Related parts
- Output Speed Sensor: The output shaft connects the wheels to the gearbox. Output speed sensor monitors the speed at which the output shaft is rotating. This car's malfunctioning sensor will lead to reduced performance & poor acceleration
Possible solutions
- Begin by removing the Output Speed Sensor (OSS) to see if it is the root of the problem. If any of its teeth are missing or have become worn, they'll need to be replaced, but the code will most likely disappear after the OSS is repaired and reinstalled
- Remember to always examine the condition of the fluid. It should be a clear red color, almost like a watered-down cranberry juice. If it appears burned or brown or dirty, then you will need to change your fluid immediately.
- Check the resistance in the TCC solenoid and internal transmission wiring at the transmission case after removing the transmission harness plug
Free on OBD DashX
P077A on OBD DashX
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