Airflow Meter
- Ensure engine is at operating temperature. With key on and engine off, check for about 5 volts at Gray/White terminal of airflow meter. If voltage is not present, check wiring to MCU. See WIRING DIAGRAMS in this section. If 5 volts exists, proceed to step 2).
- Remove cover from rear of airflow meter connector. With key on and engine off, measure voltage at Gray/Yellow wire terminal. At idle position, voltage should be about one volt. Manually move intake flap inside airflow meter. Voltage should rise steadily from one volt to about 4.5 volts as flap is moved from idle to wide open throttle position. If not, replace airflow meter.
- Turn off ignition. Disconnect airflow meter. Check resistance between airflow meter Gray/Green and Gray/Blue wire terminals, and between Gray/Green and Gray/White wire terminals. If terminals do not show continuity, replace airflow meter.
NOTE:
On 5 and 7 Series models with self-diagnostics, a short or open in airflow sensor wiring may set a trouble code 07. If code is set, MCU will operate engine with fixed injection rate (3.5-4.5 ms) and fixed ignition timing (20° BTDC) with idle switch contacts open.