Lotus Evora - Intake Air Flow

Page 14
Lotus Service Notes Section EMR
-Intake Air Flow
P0101 Mass or Volume Air Flow Circuit Range/Performance
P0102 Mass or Volume Air Flow Circuit Low Input
P0103 Mass or Volume Air Flow Circuit High Input
Description
The Mass Air Flow (MAF) sensor is incorporated into the airbox, and measures both intake air flow rate and
Intake Air Temperature (IAT). The MAF sensor uses a hot wire exposed to the airflow, which is maintained at a
constant temperature by a constant current flow. This is achieved within the sensor unit by varying the voltage
applied to the hot wire. This voltage is the output signal from the MAF sensor.
Sensor connections
Sensor Connector Description ECU Pin ECU Connector
1 IAT Signal J3 48 Way (Centre)
2 IAT Ground E3 48 Way (Centre)
3 Battery Voltage - -
4 MAF Ground J4 48 Way (Centre)
5 MAF Signal G1 48 Way (Centre)
Sensor characteristics
0 – 330 g/sec
Typical values: 1.5 – 5.0 g/sec (idle), 5.0 – 15.0 g/sec (2500rpm elevated idle no load)
P0101
Monitor:
• Continuous.
Enable Criteria:
• Enginerunning
• Enginespeed>1500rpm
• Enginespeed<3510rpm
• FuelLearnsenabled
Disable Criteria:
• P0122,P0123,P0222,P0223–Throttle/Pedalpositionfaultcodes
Malfunction Criteria:
• MeasuredMAFiscomparedtoapredictedMAFbasedoncurrentengineconditions.
• Error>40%fortime>1.5secs
Potential failure modes:
• MAFmeter
• Airinductionsystem
• Airintakehoseconnections
Diagnostic Mask:
• TheMILwillbeilluminatedifthefaultsarepresentfor2consecutivetrips
P0102
Monitor:
• Continuous.
Enable Criteria:
• Enginerunning
2009/02