What does code P1864 mean?

Q: What does code P1864 mean?

Torque Converter Clutch Circuit. P1864 on GM vehicles indicates that the powertrain control module has detected an abnormal condition in the torque converter clutch (TCC) circuit, which controls the lockup of the torque converter for improved fuel economy and reduced slip. The computer monitors the circuit for expected voltage or current feedback and sets this code when the signal is out of range, often due to an electrical fault or a mechanical issue within the transmission.

DTC codes / GM codes / P1864

P1864 · GMTorque Converter Clutch Circuit

P1864 on GM vehicles indicates that the powertrain control module has detected an abnormal condition in the torque converter clutch (TCC) circuit, which controls the lockup of the torque converter for improved fuel economy and reduced slip. The computer monitors the circuit for expected voltage or current feedback and sets this code when the signal is out of range, often due to an electrical fault or a mechanical issue within the transmission.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyProfessional

AreaTransmission

Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.