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164 RPM/Timing and Coolant Temp Sensor Info

S31 in wiring diagrams is RPM/Timing Sensor and has a 3-wire Bosch connector. It is located next to toothed front crank pulley and has preset (NON-ADJUSTABLE} air gap of .020" to .050" (.5 to 1.5mm). The resistance check is between 3-WIRE CONNECTOR center pin and outside pins. You will get no reading open between center and one outside pin and about 0.6 k ohm between center pin and other outer pin.

As for tip of sensor it is magnetic.


S7 in wiring diagrams is Coolant Temp Sensor amd has a 2-wire Bosch connector. It is located in mid thermostat housing at a 45 degree angle under top radiator hose that is attached to thermostat outlet (hidden from view from top of engine). It is not 2-spaded terminal equipped temp gauge and red light sender facing forward next to timing belt cover. The resistances shown in temp chart below are a little off from actual resistances usually found. 0C/32F is 6.0 kohm, 20C/68F is 3.0 kohm and 100C/212F about 200-300 ohms.

Attached pictures are from 24v shop manual but sensors are in the same location on 12v models.
 

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Discussion Starter #3
Steve,
Do you happen to know a current Bosch part number for the RPM/Timing Sensor for 12V (91-93) engines?

Simeon T
164 12V 04 S31 rpm/timing sensor 60560715 BOSCH 0261210047
 

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Steve is it possible to check the Timing sensor with a digital multimeter?

My car died last night - checking around for missing voltage etc - currently I have no sparks happening - I checked the leads from the timing sensor to the Motronic unit - I'm reading nothing (open circuit) - not sure if this is a magnetic unit or some kind of hall effect device (I tried checking using the diode function - no reading)

Any help appreciated on this "no sparks" problem
 

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Cancel Red Alert :rolleyes:

I just checked the wiring harness back to the Timing sensor - that plug/connector ( passenger side next to timing cams on side of wheel arch/strut) for the sensor had drifted apart - pushed it back together and I've got sparks and a running car.

Mac...
 

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Discussion Starter #6
Steve is it possible to check the Timing sensor with a digital multimeter?

My car died last night - checking around for missing voltage etc - currently I have no sparks happening - I checked the leads from the timing sensor to the Motronic unit - I'm reading nothing (open circuit) - not sure if this is a magnetic unit or some kind of hall effect device (I tried checking using the diode function - no reading)

Any help appreciated on this "no sparks" problem
Yes, check resisance between center pin and outside pins. You will get no reading open between center and one outside pin and about 0.6 k ohm between center pin and other outer pin.

As for tip of sensor it is magnetic.
 

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Cancel Red Alert :rolleyes:

I just checked the wiring harness back to the Timing sensor - that plug/connector ( passenger side next to timing cams on side of wheel arch/strut) for the sensor had drifted apart - pushed it back together and I've got sparks and a running car.

Mac...
Glad you found a simple fix.
 

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Yes, check resistance between center pin and outside pins. You will get no reading open between center and one outside pin and about 0.6 k ohm between center pin and other outer pin.

As for tip of sensor it is magnetic.
Thanks for the info Steve, that's good to know for future reference. I wasn't able to source that on the net.
 

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Thank you Steve.
 
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