Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1986 Porsche 944 Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Speed Sensor Check
NOTE:
This is an alternate test when an oscilloscope is not available.
- Secure a Fresnel lens front LED from an electronics store or use Special Test Unit (171 919 061B ). Connect a 220 ohm-1/4 watt resistor in series with one of the LED terminals.
- Connect positive LED test lead to terminal No. 8 of CU harness connector. Connect negative LED test lead to terminal No. 27 of same connector. DO NOT start engine, but operate starter. LED will flicker dimly if speed sensor is sending a signal.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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