Models Produced From March 1990

STATIC TEST

Engine Sensor Connector Bracket And Connector Terminal ID:

1. Unplug engine speed sensor harness connector (gray connector on bracket).

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

4. With ignition turned OFF, disconnect ECU connector C and check continuity in circuit between ECU terminals 1C, 2C, & 3C and sensor harness connector terminals #1, #2, & #3 respectively (should be continuous).

^ If there is no continuity in any of the wires to the ECU from sensor, check to make sure the connectors for the engine speed sensor (black connector) and crankshaft position (reference) sensor (gray connector) are not mixed up (plugged into the wrong sensor).

5. Check clearance between sensor tip and teeth of flywheel.
^ Clearance should be 1.10mm (0.043").

6. Check for excess accumulation of metal shavings or other ferrous material on the sensor tip.

If no problems have been found, but a code 2111 was displayed, then there is a poor connection at the ECU or the ECU is faulty.

DYNAMIC TEST

Engine Speed Sensor Signal:

The engine speed 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 a flywheel tooth passes the sensor tip which, when viewed on a scope, approximates a sine wave. The wave pattern should look similar to 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.