Lotus 2004 Eleven Service Notes page 165

Lotus Service Notes
Misfire
P0300 Random/Multiple Cylinder Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected
P0304 Cylinder 4 Misfire Detected
Description
A misfiring cylinder can be detected by analysing crank speed variation. As a result of a combustion event there
will be a net acceleration of the crankshaft. Subsequent to a misfire event the engine will decelerate over the
period following the missed cylinder event.
Speed changes can be characterised by observing changes in the time period for a fixed angle of rotation after
firing events. A significant change in this period, assessed by comparison to previous periods, may be attributed
to misfire on a known cylinder.
Component connections
Connector Description
1 Supply Voltage
2 Ignition Coil Feedback
3 Coil Output (Logic)
4 Ground
Malfunction Criteria
The operation of all the misfire codes is the same, the last digit relates to the misfire involved i.e. a code P0303
indicates there is a problem with coil number 3. P0300 indicates the misfire is random and not linked to one
particular cylinder.
Enable Criteria:
• Battery voltage between 10 – 16 V
• Coolant temperature between -10 – 120°C (14 – 248°F)
• Engine speed between 660 – 8010rpm
• Engine speed transient > 15rpm
• Altitude < 8000 ft (2438 m) / Baro > 756mbar
• Fuel level > 5 litres (1.3 US gallons)
• Engine load between 15 – 48% depending on engine speed
Disable Criteria: DFCO enabled (Deceleration Fuel Cut Off)
Monitor: Continuous
Limp home:
• Limit maximum engine speed to 6000 rpm
• Return the fuel system to open loop
• ECU may deactivate two cylinders, the misfiring cylinder and it's matched other i.e. 1 & 4 or 2 & 3.
Potential failure modes:
• Injector related codes, as these can cause misfire codes to be set.
• VVT or VVL codes set
• Sensor connector and wiring for signs of corrosion or loose connections
• Spark plug / Cylinder compression
• Cam timing / Damage to rocker arm assembly
Page 22
P0300
P0301
P0302
P0303
P0304
'06 M.Y. in brackets
ECU Pin
Coil 1 Coil 2 Coil 3
22 (F3) 22 (F3) 22 (F3) 22 (F3) 52 Way (Right)
52 (G1) 26 (G4) 47 (G3) 48 (G2) 52 Way (Right)
Section EMP
ECU Connector
Coil 4