1991 Mercedes Benz 300CEFACTORY OEM SERVICE PROCEDURE

Impulse Counter Readout

Enter self-diagnostics. See ENTERING SELF-DIAGNOSTICSΒ  . Turn ignition on. Ensure drive selector is in Park or Neutral position. If using impulse tester, press START button on impulse tester for 2-4 seconds maximum. If using multimeter, press diagnostic connector pin No. 2 push button for 2-4 seconds maximum. Impulse counter or multimeter will now indicate code(s) stored in memory by digital readout or by needle impulses. Pressing push button longer than 2-4 seconds will erase code in memory.

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:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.