The P0261 code on your 2022 Lexus NX indicates a low voltage condition in the cylinder 1 fuel injector circuit. This code helps identify which injector is experiencing electrical problems, allowing focused diagnosis.
Understanding P0261 in the NX
The 2022 Lexus NX offers the 2.5L four-cylinder (NX 250), 2.5L hybrid (NX 350h), or 2.4L turbo (NX 350). All use sophisticated direct injection systems requiring precise injector control. A low circuit reading indicates the ECM is detecting below-normal voltage in the cylinder 1 injector driver circuit.
What Low Circuit Means
A low reading typically indicates a short to ground somewhere in the circuit. This could occur within the injector coil itself, in the wiring between the ECM and injector, or at the connector. The injector may still fire but with altered characteristics, or it may not fire at all depending on the short's resistance.
Diagnostic Procedure
Locate cylinder 1 on your specific engine variant—it's at the timing chain end of inline engines. Disconnect the injector and measure coil resistance—compare to specifications for your engine. Check the connector for corrosion or damage. Use a wiring diagram to test circuit resistance to ground. Inspect for wiring damage near hot exhaust components.
Repair Solutions
If the injector is internally shorted, replacement is required. Direct injection injectors on the NX require fuel system depressurization before removal. Wiring shorts require careful repair using proper techniques. After repairs, clear codes and verify proper injector operation through scan tool monitoring.