Operation CHARM: Car repair manuals for everyone.

Test Point 3 - Speed Sensor

NOTE: This test requires the use of an oscilloscope. Refer to oscilloscope manufacturer's instructions for hookup and operation.

1. Disconnect engine speed sensor plug (center plug in three plug plate in left front of the engine compartment).
2. Connect oscilloscope to center and lower terminals of speed sensor connector.


Engine Speed Sensor Oscilloscope Pattern:






3. Crank engine and observe oscilloscope.

Pattern correct, proceed to step 6.
Pattern incorrect, proceed to next step.

4. Measure resistance across same terminals check in previous test.

600 - 1600 ohms, proceed to next step.
Not 600 - 1600 ohms, replace engine speed sensor. End of test.

5. Check sensor and harness wiring and sensor adjustment. If both check OK, replace engine speed sensor. End of test.
6. Measure resistance across same terminals check in previous test.

600 - 1600 ohms, proceed to next step.
Not 600 - 1600 ohms, replace engine speed sensor. End of test.

7. Sensor functioning properly. End of test.