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A problem that may cause no-start problems on a Mazda or lead to the engine running rough is a failed crankshaft position sensor.

A Mazda crankshaft position sensor (CPS) monitors the position and rotation speed of the crankshaft.

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Common symptoms of bad Mazda crankshaft position sensor include:

  • Mazda won't start
  • Intermittent Starting
  • Check Engine Light On
  • Mazda cranks but won't start.
  • Engine idles rough
  • Fault Codes: P0335, P0017, P0016

These symptoms may be intermittent in some cases. That's why it makes it hard to diagnose a bad crankshaft position sensor, especially if the check engine light has not turned on.

Follow these steps to change the crankshaft position sensor on a Mazda.

You will need


  1. Park your Mazda on level ground. Engage parking brakes. Let the engine cool down.
  2. Jack up the front right (passenger) side wheel. The CPS sensor is located on the same side that you have the serpentine belt. It is not on the transmission side.mazda 3 6 crankshaft position sensor location
  3. Remove the front wheel. Secure your vehicle with a good set of jack stands and block a tire as well, so your car doesn't roll.mazda crankshaft position sensor location
  4. Remove the plastic wheel well liner. It is held in place with several plastic clips, 8mm or 10 mm nut depending on the Mazda model.
  5. Locate the crankshaft position sensor.
  6. Unplug the electrical connector.replace crankshaft position sensor on mazda
  7. Remove two 8mm bolts.replace mazda cps sensor by removing two 8mm bolts
  8. Before removing the old crankshaft position sensor, mark the old sensor's exact position with a marker. You need to install the new CPS sensor in the same location.crankshaft position sensor replacement mazda 3 5 6 cx5 cx7 cx9
  9. Install a new crankshaft position sensor on your Mazda engine block. Notice that the mounting holes are not round but oval. This allows the sensor to be moved slightly.
  10. Before you tighten the screws, make sure that the new sensor is in the same location as the old one.


  • Use the bolt in the crankshaft center to turn the engine until cylinder 1 hits Top Dead Center (TDC) on the compression to adjust mazda crankshaft position sensor
  • You will need to align the fifth tooth to the center of the sensor magnetic tip.mazda cps replacement diy cost
  • Check with your Mazda dealer as these instructions may vary between different 2.0, 2.3, 2.5 Mazda engine sizes.

If the crank sensor fails on your Mazda, your car will refuse to start or will start intermittently.

Related Problems

Fuel Pump

  • If your Mazda is not starting, it is possible that the fuel pump has failed or is not generating enough pressure.

Ignition System

  • Spark plugs and ignition coils can also be effective and could be another reason why your Mazda does not start.