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 Mercedes Benz 560SLFACTORY OEM SERVICE PROCEDURE
Testing Airflow Sensor Position Indicator
- Loosen plug of airflow sensor position indicator so that voltage can be measured at the pins (do not disconnect plug). Start engine. Voltage at terminals No. 1-3 should be 4.5-5.5 volts. Voltage at terminals No. 1-2 should be .5-1.5 volts. If okay, go to step 2). If not okay, go to step 3).
- Stop engine and turn on ignition. Slowly deflect airflow sensor plate. Measure voltage between terminals No. 1 and 2. Voltage should increase steadily to 4.5-5.5 volts. If not okay, replace airflow sensor. If okay, test is complete.
- Stop engine. Check wires between airflow sensor position indicator and CIS-E control unit plug for continuity. Check wire routing according to wiring diagram. Resistance should be about zero ohms. If okay, go to step 4). If not okay, repair interruptions.
- Start engine. Run at idle speed (engine at operating temperature). Check on-off ratio at diagnostic socket, tester needle should oscillate. If not okay, check diagnostic socket. If okay, test is complete.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.