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Home >> Lexus >> 2002 >> IS 300 Base, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P1200: Fuel Pump Relay Circuit Malfunction >> Circuit Description

Circuit Description

Fuel pump speed is controlled in 2 stages (high and low speeds) based on engine conditions. During engine starting or under heavy load conditions, ECM turns fuel pump relay off to operate fuel pump at high speed. During idling or under light load, ECM turns fuel pump relay on to operate fuel pump at low speed. DTC will set if open or short is detected in fuel pump relay circuit for .5 seconds or more while engine is cranking. Possible causes are:

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