Check Burn-Clear Function

1992 BMW 750iLSECTION Check Burn-Clear Function

Increase engine speed once to more than 2000 RPM with engine temperature more than 140°F (60°C). Approximately .5 second after switching off the engine, the hot wire can be seen to briefly light up (burn-clear) at HLM (air cleaner cover removed). Signal can also be measured between pin No. 13 and pin No. 26 of 88-pin universal adaptor. Voltage of approximately 3.5 volts is applied at pin No. 13 to facilitate the burn-clear function (i.e. at the moment of actuation, the system voltage measured at pin No. 26 reduces by this value). The signal, however, can only be measured with a fast multimeter.

RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra 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.