Code Definition

P1860 — Torque Converter Clutch (TCC) PWM Solenoid circuit

System: Powertrain  |  Type: Manufacturer-Specific  |  Make: GM

About P1860

P1860 is a manufacturer-specific powertrain diagnostic trouble code recorded for GM vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1860 is stored, the module has detected an electrical-circuit fault in the wiring, connector, or driver associated with the named component.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

P1860 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

This DTC sets when the Transmission Control Module (TCM) detects a fault in the Torque Converter Clutch Pulse Width Modulation (TCC PWM) solenoid circuit. The TCC PWM solenoid controls the gradual apply and release of the torque converter clutch, modulating it to reduce harshness and improve driveability rather than locking it abruptly. A fault is set when the solenoid control circuit is open, shorted to ground, or shorted to voltage, or when the commanded state does not match the feedback. The driver may notice harsh or bumping lockup, no torque converter lockup, or the transmission defaultin...

Join TaT to view the complete code information and diagnostic details.

Quick Facts