2017 07 06 VAR 48 - Speed Timing Sensor

Speed Timing Sensor

What is the Speed Timing Sensor all about?

A speed/timing sensor measures the rotation of a component to determine its physical rotational speed. When it is monitored, it can be used to determine the correct air/fuel mixture, the spark advance, and variable valve timing for your engine. The speed
timing sensor is a magnetic coil that is mounted stationary to the engine block and reads the teeth on the crankshaft as it rotates. As the crankshaft spins during driving, an induction current is created around the magnetic coil. The crankshaft’s serrated
edge obstructs this magnetic field and the result gets recorded. This measurement is reported to the engine control module to determine how engine performance settings will be adjusted. If the crankshaft speed/timing sensor isn’t reading properly or
at all, the Check Engine light will come on and engine performance will be compromised.

Keep in mind:

  • There can be multiple speed/timing sensors in your vehicle as some designs monitor crankshaft speed while others monitor crankshaft and camshaft speeds.

What common symptoms indicate you may need to replace the Speed Timing Sensor?

  • Low coolant light comes is on
  • Lack of power
  • Check Engine light is on

How important is this service?

The engine performance is reduced if the speed/timing sensor is reading an inaccurate value. While the engine may still run, it will not run well and the problem should be corrected.