Code Definition

P1901 — Torque Converter Clutch Circuit Intermittent

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

About P1901

P1901 is a manufacturer-specific powertrain diagnostic trouble code recorded for Mazda vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1901 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.

P1901 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 code is set when the Transmission Control Module (TCM) detects an intermittent or erratic signal in the torque converter clutch (TCC) solenoid circuit. The TCC solenoid regulates the application of the torque converter clutch to improve fuel efficiency and reduce heat buildup. If the circuit experiences voltage fluctuations, open circuits, or unexpected disengagement, the TCM logs this fault.

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