Crankshaft Position Sensor: Testing and Inspection

CIS Turbo ECU Harness Connector (Pin # Locations):

STATIC TEST

Engine Sensor Electrical Connectors:

1. Unplug harness connector from crank position sensor lead (black connector on bracket near ignition coil).

2. Check resistance between terminals #1 and #2 of male connector.
- Resistance should be approx. 1K ohms. If not, replace sensor.

3. Check resistance between terminals #1 and #3, and between terminals #2 and #3 of male connector.
- Resistance should be infinite (no continuity). If there is any continuity (even if resistance is very high) replace sensor.

4. Check for open or grounded circuit between ECU terminals #13, #12, and #28, and sensor female harness connector terminals #1, #2, and #3 respectively, with ECU harness connector disconnected.


5. Check clearance between sensor tip and reference pin in flywheel.
- Clearance should be 1.10mm (0.043").

If no problems have been found, but a code 2112 was displayed, check distributor basic adjustment and hall sensor. If these also check out OK, then the ECU is faulty.

DYNAMIC TEST

Crankshaft Position (Reference) Sensor Signal:

The crankshaft position sensor can be tested dynamically with the use of an oscilloscope. When the engine is running, the sensor will produce an alternating current wave pulse each time the reference pin passes the sensor tip. The wave pattern should look like that shown in the diagram, and can be observed on a scope by probing terminals #1 and #2 of the sensor connector (use appropriate break-out box or parallel connector test leads).
Many automotive oscilloscopes are designed only to display primary and secondary ignition patterns and are not able to perform this type of test. To find out if your scope has this capability, or for correct procedures on hooking up a scope see the manufacturers instructions for your particular scope.