Cylinder Identification Sensor: Testing and Inspection

Note: For 86 and 87 cars, two types of sensors were available
a. A pulse type that picked up a signal from the vibration damper, or
b. An inductive pickup mounted on the #1 spark plug wire).
Inspect the vehicle to determine which system is used, and test accordingly. Each car will have one type of sensor or the other (not both).
The TDC sensor is an inductive pickup located above the crankshaft vibration damper. The cylinder identification sender is mounted on the #1 spark plug wire, under the distributor cap cover.

TDC sensor:

Using an Ohmmeter, check the resistance between terminals 8, 9, and 10 on the engine diagnostic plug. The resistance should be:
Between 8 and 10 80 ± 10 Ohms, at 23 ± 5°C (73 ± 9°F)
Between 8 and 9, or 10 and 9 at least 60K Ohms
Replace the sensor if it is not within specification.*

Fig. 70 Inductive cylinder identification sender:

Cylinder identification sender:

Using an Ohmmeter, check the resistance between terminals 8, 9, and 10 on the engine diagnostic plug. The resistance should be:
Between 8 and 10 less than 1 Ohm, at 20°C (68°F)
Between 8 and 9, or 10 and 9 at least 60K Ohms
Replace the sensor if it is not within specification.*

* The TDC sensor, and the Cylinder identification sensor are used for checking ignition timing only. They have no Motronic function.