The engine system, in combination with the engine control module (ECM) or powertrain control module (PCM), starts the engine P1834 code solenoid valve to regulate oil compression to the engine mechanism that is installed in the valve system to switch valve timing between Low and High. If the engine solenoid controller has an open or short circuit, a DTC is stored. The general meaning of the code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 1 for MFG – Manufacturer Specific. 8 for Ignition System Or Misfire. 3 for Cruise Control Servo Indicates Low and 4 for Cruise Vehicle Speed/Set Speed Difference Too High.