Lotus Evora Service Notes page 139

Lotus Service Notes
Misfire
P1301 Misfire level causing emissions increase
P1302 Misfire level causing catalyst system damage
Description
When the engine misfire reaches a high enough percentage the engine emission output levels can exceed the
allowed limits, this will produce the fault code P1301.
If the misfire percentage is high enough and there is a possibility that the catalyst may be damaged then code
P1302 will be set. To prevent catalyst damage the ECM may take action to either shut down the engine bank
containing the misfiring cylinder and limit the engine speed to 4000rpm, or limit the throttle opening if there is
more than one cylinder misfiring.
See misfire faults P0300, P0301, P0302, P0303, P0304, P0305, P0306
Monitor:
• Continuous
Enable Criteria:
• Battery voltage between 10 – 16 V
• Coolant temperature between -10 – 120°C (14 – 248°F)
• Engine speed between 480 – 8010rpm
• Engine speed transient > 15rpm
• Altitude < 8000 ft (2438 m) / Baro > 756mbar
• Fuel level > 5 litres (1.3 US gallons)
• Engine load greater than 14 – 25% depending on engine speed
Disable Criteria:
• DFCO enabled (Deceleration Fuel Cut Off)
• Rough road
• MAF faults
Malfunction Criteria:
• P1301 Emissions Failure – Misfire percentage > 7% measured over 1000 engine revolutions.
• P1302 Catalyst Damage Failure – Misfire percentage > 16.6% - 40% depending on engine speed and load,
measured over 200 engine revolutions.
Potential failure modes:
• Injector related codes, as these can cause misfire codes to be set.
• VVT codes set
• Sensor connector and wiring for signs of corrosion or loose connections
• Spark plug / cylinder compression
• Cam timing / damage to rocker arm assembly
• Fuel pressure
Diagnostic Masks:
• For a P1301 fault code the MIL will be illuminated immediately.
• For a P1302 fault code the MIL will be illuminated immediately and the ECM will take action to prevent
catalyst damage.
Notes:
• Misfire learns are calculated during DFCO (Deceleration Fuel Cut Off)
2009/02
Section EMR
Page 67