Circuit Description

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

The DTC P1693 Rocker Arm Actuator System Stuck Off diagnostic monitors operation of rocker arm oil control solenoid. Rocker arm oil control solenoid enables Powertrain Control Module (PCM) to operate the high speed cam system. High speed cam system significantly increases valve lift at engine speeds above 6000 RPM. A second camshaft lobe with a high lift profile is cast into each camshaft, alongside low/medium speed lobes. Unique rocker arms follow both high speed and low/medium speed cam lobes. At engine speeds below 6000 RPM, low/medium speed cam lobes operate rocker arms. When rocker arm oil control solenoid is turned ON between 6000-8200 RPM, rocker arms are operated by high speed cam lobes. Rocker arm oil control solenoid is controlled by a Pulse Width Modulated (PWM) signal from PCM.

The rocker arm oil pressure switch detects oil pressure when oil is flowing thorough the rocker arm oil supply system. When the rocker arm oil control solenoid is ON, the oil pressure switch opens and the signal circuit to the PCM goes high. A DTC P1693 sets when the signal circuit of the rocker arm oil pressure switch remains low even when engine the speed is more than 6,000 RPM.