Ignition Hall Effect Sensor: Testing and Inspection

CIS-E III Control Unit Harness Connectors (Pin # Locations):

This test requires that the battery is fully charged and battery voltage does not drop below 9 volts while cranking.
NOTE: If there is spark present at the coil wire while cranking, it is not necessary to check the hall sensor.

If there is no spark:

Power Output Stage, Ignition Coil, And Connector:

1. Remove harness connector from ignition output stage (power transistor next to ignition coil).

2. Leave output stage disconnected and disconnect harness connector from distributor.

3. Turn ignition "on" and check voltage between distributor harness connector terminals #1 (ground, BRN/W wire) and #3 (power from ignition control unit, R/BLK wire).
- Voltage should be 9-11 volts. If not, check for open or grounded circuit between ignition control unit terminal #4 and distributor harness connector terminal #3. Also check for open circuit between distributor harness connector terminal #1 and ignition control unit terminal #10. Repair as necessary. If no problems are found in wiring, and there is still no voltage present, then the ECU is faulty. If voltage is present, continue with test.

4. Slide rubber boot away from distributor connector to gain access to the back of the connector terminals, and re-connect to distributor.

5. Connect LED test light between terminal #2 (G/W wire) of distributor connector and ground.

6. Crank engine and observe LED.
- LED should flicker when connected with proper polarity. If not then there is an open circuit between distributor harness connector terminal #1 and ignition control unit terminal #10, or the hall sensor is faulty and must be replaced. If LED does flicker, hall sensor is OK. If hall sensor checks OK and fault code 2122 was displayed, check for open or grounded circuit between distributor harness connector terminal #2 (G/W wire) and ignition control unit terminal #24. Also check for open or grounded circuit between ignition control unit terminal #17 and fuel control unit terminal #30.

7. Connect LED test light to terminals #2 (G/W wire) and #3 (BRN/R wire) of power output stage harness connector.

8. Crank engine and observe LED.
- LED should flicker when connected with proper polarity. If it does, check for battery power at output stage harness connector terminal #1 (black wire). Battery voltage should be present. If not check for open circuit between harness connector terminal #1 and terminal B15 of fuse relay panel. If there is power at terminal #1, but still no spark, either the output stage or the coil is faulty, most likely it is the power output stage (ignition coils rarely go bad).
- If the LED does not flicker, reverse polarity of LED connections and re-check. If it still does not flicker, Check for open circuit between terminal #3 and ground. Check also for open or grounded circuit between output stage connector terminal #2 and ignition control unit connector terminal #16, repair if necessary. If no problems are found up to this point, and LED still does not flicker, then the ECU is faulty.

DYNAMIC TEST

Hall Sensor Signal:

The hall sensor can be tested dynamically with the use of an oscilloscope. When the engine is running, the sensor will produce a square wave pulse each time a window of the trigger wheel passes the sensor. 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 while the engine is running.
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.