Misfire Monitoring (page 2 of 2)

The following are the TestBook drive cycles used on Discovery II with V8 engines and Bosch 5.2.1 engine management system:

⇒ Drive cycle A: 1. Switch on the ignition for 30 seconds. 2. Ensure engine coolant temperature is less than 60°C (140°F). 3. Start the engine and allow to idle for 2 minutes. 4. Connect TestBook and check for fault codes.

⇒ Drive cycle B: 1. Switch ignition on for 30 seconds. 2. Ensure engine coolant temperature is less than 60°C (140°F). 3. Start the engine and allow to idle for 2 minutes. 4. Perform 2 light accelerations (0 to 35 mph (0 to 60 km/h) with light pedal pressure). 5. Perform 2 medium accelerations (0 to 45 mph (0 to 70 km/h) with moderate pedal pressure). 6. Perform 2 hard accelerations (0 to 55 mph (0 to 90 km/h) with heavy pedal pressure). 7. Allow engine to idle for 2 minutes. 8. Connect TestBook and with the engine still running, check for fault codes.

⇒ Drive cycle C: 1. Switch ignition on for 30 seconds. 2. Ensure engine coolant temperature is less than 60°C (140°F). 3. Start the engine and allow to idle for 2 minutes. 4. Perform 2 light accelerations (0 to 35 mph (0 to 60 km/h) with light pedal pressure). 5. Perform 2 medium accelerations (0 to 45 mph (0 to 70 km/h) with moderate pedal pressure). 6. Perform 2 hard accelerations (0 to 55 mph (0 to 90 km/h) with heavy pedal pressure). 7. Cruise at 60 mph (100 km/h) for 8 minutes. 8. Cruise at 50 mph (80 km/h) for 3 minutes. 9. Allow engine to idle for 3 minutes. 10. Connect TestBook and with the engine still running, check for fault codes.

NOTE: The following areas have an associated readiness test which must be flagged as complete, before a problem resolution can be verified:

• catalytic converter fault;
• Evaporative loss system fault;
• HO₂ sensor fault;
• HO₂ sensor heater fault.