Walker Products Oxygen Sensor Training Guide

Testing the Oxygen Sensor

DENSO Oxygen Sensor Diagnosis

DENSO Lambda-Oxygen Sensor

Bosch Testing of Oxygen-Lambda Sensors


So, crankshaft Camshaft Sensors, Are Both Required By Distributorless Ignition Systems. Consequently, engines rely on signals from both, to determine when to the fire spark and inject fuel.

So, the (ECM) uses signal pulses from, both sensors to gain information:

  • To calculate when a particular cylinder, is approaching top dead center.
  • To decide when it is on a, compression or an exhaust stroke.

But, if either signal is lost, the (ECM) may decide to, shut down ignition, injection or both. In addition, sensor failures are extremely common on certain makes. So, it was not that long ago, that a failed sensor would cause; a no start or an engine that just died. But, many engines can overcome this problem, with the limp home feature.

Above all, the relationship between the two signals, is as important as the signals themselves. Also, some (DTC)s are related to the loss of, camshaft/crankshaft signal correlation or synch.

Common problems that can cause issues with, (CMP)/(CKP) signals include:

  • Accumulation of dirt, on the sensor tip.
  • Stretched timing belts and chains.
  • Cracked flex-plates and wiring connector problems.
  • Excessive end play on crankshafts and camshafts, can also cause variations in the signal.

Finally, both sensors usually fail slowly; as the signal to the (PCM) weakens.

Sensor Locations:

  • So, the Camshaft Position sensor; is located in the cylinder head.
  • In addition, the Crankshaft Position sensor, is located in the timing cover or on the block.

A lot of people confuse the camshaft position sensor; with the crankshaft position sensor. Because, they sound similar. But, there’s a big difference between the two; as they perform different functions in the vehicle. And, have different symptoms, when something goes wrong with them.

How to Replace a Camshaft Position Sensor

  1. Disconnect the negative battery cable.
  2. Locate the sensor. It’s usually on the top, front, or rear part of the engine. It will likely have a 2-3 wire connector attached.
  3. Release the tab on the sensor to disconnect the wires from the sensor.
  4. Remove the mounting bolt which attaches the sensor to the engine. It’s usually an 8mm or 10mm bolt.
  5. Pull the sensor off with a slight twist.
  6. Apply a bit of engine oil to the O-ring of the new senor.
  7. Install the new camshaft position sensor and secure with the mounting bolt.
  8. Reconnect the wire connector to the sensor.
  9. Reconnect the negative battery terminal.

How difficult is it to replace a bad crank sensor?

It depends on the sensor’s location. If it is relatively easy to reach, replacing it is a simple swap. Loosen the bolt that holds the sensor in place; pull it out and insert the new sensor. On some vehicles, however, the sensor is really buried and is difficult to reach. Other components may have to be removed, before the sensor can be replaced.

Thank You !