Check if your BMW is ready for an emissions inspection

An emissions inspection checks the car's OBD readiness monitors: self-tests the engine module runs while you drive (catalytic converter, oxygen sensors, evaporative system and more). A car can fail the inspection with no warning light on, just because its monitors haven't finished running, for example after the battery was disconnected or the fault codes were cleared.

AutoLingo for BMW reads the monitors straight from the engine module, so you know before you go.

Which BMWs

BMWs with OBD2 (in the US, every car from 1996 on) whose engine module AutoLingo for BMW reads: about 70 engine module versions, the E46's MS42 and MS43 included. Not yet: the Siemens engine modules of some early M52 and M62 engines.

Before you start

  • The AutoLingo for BMW adapter plugged in and connected.
  • Ignition on.

Step by step

  1. Open the Service tab.
  2. Under “Emissions readiness”, tap Read next to “OBD readiness”.
  3. Read the result: whether the check-engine light is on and how many emissions codes are stored, then the verdict (“All monitors have run — ready for an emissions inspection.” or “Not ready for inspection.”) and each monitor: ✓ finished, ✗ not ready, – not reported by this module.

Good to know

  • Nothing is changed on the car: it's a read.
  • A monitor becomes ready after the car completes its normal drive cycles. If some aren't ready, drive the car normally for a few days (city and highway) and check again before the inspection.
  • If the check-engine light is on, read the faults on the Faults tab first: a car with the light on fails the inspection whatever the monitors say.

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