The following diagram shows how a drive cycle is set (test drive) in order for all the systems to be monitored once. The test conditions can be created in any desired order after startup.

Fig 1: Identifying Drive Cycle Graph

Courtesy of BMW OF NORTH AMERICA, INC.

Engine cold start, idling, approximately 3 minutes. Evaluated:
- Secondary Air System
- Evaporative Leak Detection (LDP Equipped Vehicles)
Constant driving at 20 to 30 MPH, approximately 4 minutes. Evaluated:
- Oxygen Sensors - Achieved "Closed Loop" Operation
- Oxygen Sensors - Response Time and Switching Time (Control Frequency)
Constant driving at 40 to 60 MPH, approximately 15 minutes (sufficient vehicle coasting phases included). Evaluated:
- Catalytic Converter Efficiency
- Oxygen Sensors - Response Time and Switching Time (Control Frequency)
Engine idling, approximately 5 minutes. Evaluated:
- Tank-Leak Diagnosis (DM TL Equipped Vehicles after KL 15 is switched OFF)

NOTE: The diagnostic sequence illustrated above will be interrupted if:

The engine speed exceeds 3000 RPM.
The driving speed exceeds 60 MPH.
Large fluctuations in the accelerator pedal position.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Drive Cycle

Use the Manual With the Right Hardware

When to See a Mechanic