Code Definition

P1652 — Idle Air Control Valve Control circuit

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

About P1652

P1652 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 P1652 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.

P1652 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 fault code sets when the Engine Control Module (ECM) detects an electrical fault in the Idle Air Control valve control circuit. The IAC valve regulates idle speed by adjusting the amount of air that bypasses the throttle plate, and the ECM drives it to hold a stable idle under varying loads. If the valve does not respond to ECM commands because of a short, an open circuit, or an actuator failure, the ECM stores this code. The driver may notice an unstable, high, or low idle, stalling, especially on cold start or with accessories on, and a check engine light.

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