P083B

What it means

P083B is a generic powertrain code meaning the transmission control unit has found that the signal from transmission fluid pressure sensor or switch 'G' is out of its expected range or does not agree with what the transmission should be doing. The signal is present and electrically plausible, but it does not match the commanded gear, solenoid duty or other pressure readings. Which hydraulic circuit 'G' refers to depends on the vehicle and transmission, so check the manufacturer data for your model.

Symptoms

• Gearbox warning light or malfunction indicator lamp on
• Harsh, delayed or flared gear changes
• Transmission stuck in limp mode or a fixed gear
• Slipping under load or loss of drive in certain gears
• Reduced performance or poor fuel economy

Possible causes

• Low, degraded or contaminated transmission fluid, or the wrong fluid type or levellikely
• Faulty or drifting pressure sensor or switch Glikely
• Damaged wiring, poor connector contact or corrosion in the sensor circuit, including fluid ingresspossible
• Sticking or worn valve body, pressure control solenoid or shift solenoid causing real pressure deviationpossible
• Blocked transmission filter or restricted fluid passages reducing pressurepossible
• Worn pump or internal clutch or seal leakage causing genuinely low pressurerare
• Fault in the transmission control unit or outdated software, where a known issue is documented for the modelrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting gear, fluid temperature, speed and load when the code set.
2. Check for related transmission codes, such as other pressure sensor, solenoid or gear ratio faults, as they help to narrow down the circuit.
3. Check the transmission fluid level and condition using the manufacturer's procedure, noting that many modern units need a set fluid temperature. Look for a burnt smell, metal debris or foaming.
4. Inspect the sensor wiring and connector for chafing, corrosion, fluid contamination and loose pins, and check the harness for damage.
5. Check the sensor supply voltage, earth and signal using the wiring diagram, and compare the live pressure reading with the expected value at idle and when the gear is changed.
6. Compare the sensor reading with the commanded pressure using live data, and check whether it follows solenoid commands.
7. Check for a leak, a blocked filter or a sticking valve body if the sensor and wiring pass, following the manufacturer's procedure.
8. Check for a technical service bulletin or a software update relevant to the model and fault.

How to fix

• Correct the fluid level, or replace the fluid and filter with the specified type if it is degraded or contaminated.
• Replace the faulty pressure sensor or switch G and clear the code, then road test.
• Repair or replace damaged wiring and connectors, and clean or replace corroded terminals.
• Repair or replace the valve body, pressure control solenoid or shift solenoid if they are sticking or faulty.
• Overhaul or replace the transmission if there is internal wear or low pump pressure.
• Update the control unit software only if the manufacturer lists it as a fix for the fault.

Can I keep driving?

Nearby codes

• P083AGenericTransmission Fluid Pressure Sensor/Switch G Circuit
• P083CGenericTransmission Fluid Pressure Sensor/Switch G Circuit Low