Code Definition

P1400 — Sub-Throttle Position Sensor fault

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

About P1400

P1400 is a manufacturer-specific powertrain diagnostic trouble code recorded for Toyota vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1400 is stored, the module has detected a sensor-related fault — the reported value from the named sensor is out of spec.

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.

P1400 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 Toyota DTC sets when the Engine Control Module (ECM) detects an abnormal signal from the secondary throttle position sensor, also called the sub throttle sensor, fitted to engines with a dual throttle system. This sensor monitors the angle of the secondary throttle valve, and the ECM compares its signal against the main throttle sensor and its own control commands. The code logs when the signal is out of range, inconsistent with the main throttle sensor, or unresponsive to commands. Depending on the strategy, the ECM may limit engine output or default the secondary throttle, with symptoms...

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