P083C: Transmission Fluid Pressure Sensor/Switch G Circuit Low

What does P083C mean?

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.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Check engine or transmission warning lamp on
• Limp mode with substitute gear or limited ratio
• Harsh or delayed shifts

Common causes

• High Signal wire shorted to ground, or open on duty-cycle sensors
• High Sensor faulty or switch stuck closed
• Medium 5 V supply missing
• Medium Valve stuck applied, so the switch reports pressure correctly
• Low Control module

Likelihood is a general estimate across vehicles; your make and model may differ.