Powertrain, generic · Transmission
P084C Transmission Fluid Pressure Sensor/Switch H Circuit Low
Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible
Transmission fluid pressure sensor/switch H is the last of up to eight pressure inputs (A to H) in SAE J2012; the letter is the maker's choice. Documented uses are rare: Mitsubishi sets P084A on its Jatco CVT8 (F1CJC/W1CJC) and Ford P084B on the 2020–23 Explorer 3.3 full hybrid. For P084C no maker is documented. It means the signal is too low: a switch closed although no pressure is expected, a sensor below its lower limit through a short to ground or missing 5 V supply, judged like A and B under California's rule for gearbox inputs.
Likely causes
Signal wire shorted to ground, or open on duty-cycle sensors
Sensor faulty or switch stuck closed
5 V supply missing
Valve stuck applied, so the switch reports pressure correctly
Control module
Symptoms
- Check engine or transmission warning lamp on
- Limp mode with substitute gear or limited ratio
- Harsh or delayed shifts
Repair estimate
DifficultyHardWorkshop job
Parts and labour€120–900
Time1–5 h
Typical range across vehicles; the real cost depends on what the testing finds.
Parts involved
transmission fluid pressure sensortransmission valve bodytransmission wiringtransmission control module
Related codes
References: law.cornell.edu, gearsmagazine.com.