Powertrain, generic · Transmission
P083C Transmission Fluid Pressure Sensor/Switch G Circuit Low
Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible
Transmission fluid pressure sensor/switch G is one of up to eight pressure inputs (A to H) that SAE J2012 provides for automatic gearboxes. No maker could be found that uses the letter G: GM's tables up to 2025, Ford's summaries and Allison stop at A to E. The description therefore follows the general rule for gearbox inputs in California's OBD regulation, which demands circuit and plausibility checks, and the logic of the A and B codes. P083C means the signal is too low: a switch is closed although no pressure is expected, a sensor is below its lower limit through a short to ground or a missing 5 V supply.
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.