This bulletin applies to 2002-2006 Acura RSX and 2007-2012 RDX vehicles. The malfunction indicator light (MIL) may be on with diagnostic trouble code (DTC) P2646 (rocker arm oil pressure switch circuit low voltage) or P2647 (rocker arm oil pressure switch circuit high voltage). Note that the symptom may be intermittent and you may not be able to duplicate it after clearing the DTC. The rocker arm oil pressure switch may fail intermittently. The correction involves replacing the rocker arm oil pressure switch.
Remove the power steering high-pressure hose bracket mounted on the valve cover for access to the valve cover. Remove the rocker arm oil pressure switch and the O-ring. Install a new switch part number (P/N) 37250-PNE-G01 and the 13mm x 1.5mm O-ring P/N 91319-PAA-A01.
Torque the oil pressure switch to 16 lb-ft. Reinstall the rocker cover and power steering hose bracket. Clear the DTC(s) with the Honda & Acura Diagnostic System (HDS).
Replace the rocker arm oil pressure switch and O-ring. Torque the switch to 16 lb-ft (22 Nm).