Lavida Steering Causes RPM Increase
1 Answers
Most modern vehicle steering systems utilize hydraulic power steering. The power source for hydraulic assistance comes from an engine-driven steering hydraulic pump. Small-displacement engines cannot provide sufficient power to drive the steering pump at idle. Therefore, when the engine's idle speed drops dangerously low due to powering the steering pump (risking stalling), the engine control unit (ECU) will increase engine RPM to ensure adequate power output for steering pump operation. Similarly, activating air conditioning cooling at idle will also cause engine RPM to rise. When driving the AC compressor threatens to stall the engine by reducing idle speed, the ECU increases RPM to deliver sufficient power for compressor operation. In both scenarios, idle RPM will be higher than normal. Large-displacement engines can adequately power hydraulic pumps even at idle, so steering while stationary in neutral won't cause noticeable RPM fluctuations in premium vehicles.