Low, degraded or contaminated transmission fluid; Faulty or sticking shift solenoid or valve controlling the 2-3 shift; Wiring or connector fault in the solenoid or transmission harness (chafing, corrosion, poor contact); Worn clutch pack or band, or internal hydraulic leak causing slip on the 2-3 shift; Blocked filter or worn valve body passages causing low or erratic line pressure; Faulty input or output speed sensor giving incorrect ratio readings; Fault within the transmission control unit or outdated software, where a known issue exists for that model.

P0782

2-3 Shift.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
7: AreaTransmission
82: FaultThe specific fault in that area

What it means

P0782 is the generic code for a fault in the 2-3 shift of an automatic transmission. The transmission control unit commanded a shift between second and third gear and saw that it did not happen as expected, for example through the wrong gear ratio, excessive slip or a flare in engine speed during the change. The exact test and the parts involved depend on the make, model and transmission.

Symptoms

Harsh, delayed or flaring shift between second and third gear
Transmission stuck in second gear or going into limp mode
Engine revs rising without matching acceleration during the 2-3 change
Gearbox warning light or malfunction indicator lamp on
Poor acceleration or reduced fuel economy
Possible additional shift or ratio codes stored

Possible causes

Low, degraded or contaminated transmission fluidlikely
Faulty or sticking shift solenoid or valve controlling the 2-3 shiftlikely
Wiring or connector fault in the solenoid or transmission harness (chafing, corrosion, poor contact)possible
Worn clutch pack or band, or internal hydraulic leak causing slip on the 2-3 shiftpossible
Blocked filter or worn valve body passages causing low or erratic line pressurepossible
Faulty input or output speed sensor giving incorrect ratio readingspossible
Fault within the transmission control unit or outdated software, where a known issue exists for that modelrare

How to diagnose

Read all stored codes and freeze frame data, noting gear, speed, load and fluid temperature when the fault set
Check the transmission fluid level and condition (colour, smell, debris) following the manufacturer's procedure for that gearbox
Inspect the transmission wiring and connectors for damage, corrosion, fluid ingress and chafing
Check live data for gear commanded versus gear achieved, input and output speed and slip across the 2-3 shift
Test speed sensor signals and compare them with expected values for the model
Test solenoid resistance and operation against specification, and check for supply and ground at the connector
Check line pressure with a pressure test where the transmission design allows
Check for manufacturer service bulletins or software updates relevant to the vehicle

How to fix

Correct the fluid level and renew degraded fluid and filter using the specified type
Repair or replace damaged wiring or connectors in the transmission harness
Replace a faulty shift solenoid or speed sensor
Overhaul or replace the valve body if worn or sticking
Repair or rebuild the transmission if clutches, bands or seals are worn
Update the control unit software only if a known fault for that model calls for it

Can I keep driving?

Medium severity

Short, gentle driving to a garage is usually possible, but continued use with slipping or harsh shifts can cause further internal damage. Book diagnosis soon and avoid heavy loads or towing; if the car is stuck in limp mode or slips badly, stop driving.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.