Code Definition

P1123 — Throttle Position Sensor In Range But Higher Than Expected

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

About P1123

P1123 is a manufacturer-specific powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1123 is stored, the module has detected a signal or supply voltage higher than the expected operating range; a plausibility fault — the measured value is in the electrical range but is not consistent with expected operating behaviour; and 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.

P1123 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

The Engine Control Module (ECM) monitors the Throttle Position Sensor (TPS) signal voltage to confirm that it corresponds correctly to the actual throttle plate position and engine operating conditions. DTC P1123 is set when the TPS signal remains within the valid voltage range (typically 0.5–4.5 V) but is consistently higher than the expected value for the given engine speed, load, or accelerator pedal position. This indicates that the sensor or related circuit is reporting an abnormally high throttle opening even though the system logic does not demand it.

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