Drive Cycle

DESCRIPTION
The Drive Cycle assists in identifying an OBD II system problem through total monitor testing (completing a Trip and the Catalyst Efficiency Steady State Monitor).

PURPOSE
The primary intention of the OBD II Drive Cycle is to clear the DTC P1000. However, a rerun of a certain part of this drive cycle will verify the repair of a particular monitor system.

DIAGNOSTIC NOTES:

- For HO2S monitor repair verification, perform Steps 2 through 6 and Steps 11 and 12.

- For Comprehensive Component monitor repair verification, perform Steps 1 through 9 and Steps 11 and 12.

- For all other monitor repair verification, perform the entire OBD II Drive Cycle if directed here from the EEC-V Pinpoint Tests.

A scan tool can be installed in the vehicle before the drive cycle to observe DTC output. A scan tool can be used anytime through the course of the drive cycle to observe monitor completion status (On-board Readiness Menu) or Trip status (PID Monitor Data Record Function). If the driver is working alone, it is recommended that the scan tool be used after the drive cycle is complete to observe the system status.

CAUTION
Strict observance of posted speed limits and attention to driving conditions are mandatory when proceeding through the following drive cycle. Very rough road surfaces may prevent the HO2S and catalyst efficiency steady state monitors from completing.

PROCEDURES
In the event that a particular drive mode of the OBD II Drive Cycle is interrupted before completion, repeat this drive mode. Once started, the engine must not be turned off at any time throughout the drive cycle. The summary chart on the next page shows a graphic representation of a drive cycle.






1. Start the engine.

2. Drive the vehicle in any convenient manner for four to six minutes. Any drive mode is acceptable. However, a vehicle at idle for the entire six minute duration of time cannot bring the engine to proper operating temperature.

3. Continue driving the vehicle until the engine has reached the normal operating temperature of approximately 180°F (82°C) or greater (Check ECT PID).

4. Idle for 45 seconds.

5. Accelerate to 45 mph at 1/4 throttle (elapsed time is about 10 seconds).

6. Drive to accumulate at least four minutes in the range of 30 to 45 mph. If stop and go conditions occur, the accumulative time must be within the 20 to 45 mph range. No Wide Open Throttle (WOT) conditions should be encountered.

7. Drive the vehicle at a speed between 30 and 40 mph maintaining a steady throttle position for at least one minute.

8. Decelerate and idle for at least 1 minute.

9. Accelerate to 55 mph at 1/2 throttle (elapsed time is about 10 seconds).

10. Cruise at a speed between 40 and 65 mph (follow the posted speed limit) maintaining a steady throttle position for at least 80 seconds.

11. Bring vehicle down to idle.

12. While the ignition key is On (vehicle at idle or engine Off), check for Continuous Memory DTCs using the scan tool.

- For SYSTEM PASS (All Monitors Successfully Tested): No further action is necessary.

- For DTC P1000 only: Check monitor completion status (On-board Readiness Menu) and repeat the drive cycle.

- For DTC P1000 with other DTCs: Check monitor completion status (On-board Readiness Menu), and return to Diagnostic Subroutines for repair action. Reading Diagnostic Trouble Codes

- For Any DTCs without P1000: Return to Diagnostic Subroutines for repair action. Reading Diagnostic Trouble Codes