What does it mean?
In electronically controlled automatic transmission vehicles, the 2-3 shift solenoid is responsible for actuating hydraulic circuits to engage clutches or bands that shift gears inside the automatic transmission. Shift solenoids are controlled either by a Transmission Control Module (TCM) or by the Engine Control Unit/Powertrain Control Module (ECU/PCM). The control circuit can be power-controlled or ground-controlled depending on the application.
Some vehicles automatically test the circuit even when the gear is not in use; the 2-3 shift solenoid can be an on/off solenoid or a duty cycle controlled solenoid. The PCM or TCM looks for an inductive kick to determine if the solenoid is functioning correctly even when it is not in use. This brief activation is too quick for the solenoid to actually cause a shift in the transmission. When the solenoid is turned on and off, the magnetic field collapses, sending a slightly higher voltage to the PCM, which is used to determine if the solenoid is working properly. Note: This DTC is almost identical to P0781, P0783, P0784, and P0829.
Symptoms
Symptoms of a DTC P0782 may include:
Check Engine Light illuminated (Malfunction Indicator Lamp/MIL)
The vehicle will not shift from 2nd to 3rd gear
This condition may turn on the Check Engine Light and possibly disable transmission controls entirely, resulting in a failsafe mode that will only allow one default gear depending on the vehicle’s condition with all solenoids deactivated.
Causes
Potential causes of a P0782 code include:
2-3 shift solenoid failure
Electrical short to power – pinched wires
Electrical short to ground – pinched wires
Open power or ground circuit wiring – disconnected or loose connections
Internal TCM or PCM failure
Possible Solutions
Disconnect the PCM or TCM wiring harness, depending on the application, and using an electrical diagram as a reference, check for excessive resistance or an open in the control circuit. Using a Digital Volt-Ohm Meter (DVOM) set to the Ohms scale, check the resistance on the 2-3 solenoid’s power and ground sources to determine if there is an open circuit or excessive resistance in the 2-3 solenoid. Visually inspect for pinched, disconnected, or loose wires on the harness connectors.
Short to Power: Disconnect the positive battery cable and the wiring harness connector at the transmission and check for continuity using the DVOM between the power source and the solenoid circuit wiring with the key in the On/Engine Off (KOEO) position as well as with the key off.
Short to Ground: Disconnect the positive battery cable and the wiring harness connector at the transmission and check for continuity using the DVOM between the 2-3 solenoid power source and a known good ground.
TCM or PCM Failure: Using an advanced scan tool capable of controlling solenoids, manually activate the 2-3 shift solenoid. It may be necessary to manually activate the transmission control relay on some vehicles if power is not present at the transmission wiring harness connector. If no scan tool is available, it will be necessary to monitor the 2-3 solenoid circuit to determine if the TCM or PCM is sending a power or ground signal to the 2-3 solenoid during vehicle operation.