Code Definition

P1120 — Throttle motor position sensor 1 circuit fault

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

About P1120

P1120 is a manufacturer-specific powertrain diagnostic trouble code recorded for Acura vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1120 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.

P1120 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 throttle position sensor 1 (TPS1), which is built into the electronic throttle body and reports the angle of the throttle plate driven by the throttle motor. The TPS1 signal must stay within a calibrated voltage range for a given throttle angle and must correlate with the second sensor, TPS2, which moves in the opposite direction for redundancy. DTC P1120 sets when the ECM finds the TPS1 voltage outside the expected range, erratic, or inconsistent with TPS2 for a calibrated period. When this fault is active the ECM usually limits throttle authority and ...

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