Reading Diagnostic (Flash) Codes
- With ignition switch in RUN position and after depressing accelerator pedal 5 times to WOT, CHECK ENGINE light comes on for 5 seconds to indicate self-diagnostic feature is preparing to output diagnostic codes. See Fig 1
.
- CHECK ENGINE light then turns off for 0.5 second (awaiting synchronization signal), comes on for 2.5 seconds (light check) and again turns off for 2.5 seconds (wait for readout). Last 2.5 second pause tells technician to wait for diagnostic code readout.
- Next CHECK ENGINE light on/off periods represent diagnostic codes stored. CHECK ENGINE light will be on or off for 0.5 second with a 2.5 second pause between each code digit and a 2.5 second pause between each code. See Fig 1
.
Courtesy of BMW OF NORTH AMERICA, INC.