Code Definition

P1200 — Fuel Pump Relay circuit

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

About P1200

P1200 is a manufacturer-specific powertrain diagnostic trouble code recorded for Lexus vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1200 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.

P1200 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

On this Lexus the Engine Control Module (ECM) controls the fuel pump relay, sometimes called the circuit opening relay, to switch power to the fuel pump. DTC P1200 sets when the ECM detects a fault in the fuel pump relay control circuit, such as an open, a short, or a feedback voltage that does not match the commanded state. The relay energizes the fuel pump during cranking and running and drops out when the engine stops. When this code is stored the engine may fail to start, stall, or run poorly due to inadequate fuel delivery.

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