Readiness Code

CAUTION:

When performing the Readiness drive cycle operation, pay strict attention to driving conditions and observe and obey all posted speed limits.

Readiness code description

Diagnostics are performed at regular intervals during normal vehicle operation. After repairing an emissions related system, a readiness code is generated by road testing the vehicle.

If a malfunction is recognized during the drive cycle, it will be stored in the DTC memory.

The OBD drive cycle operation will be monitored with a hand held diagnostic tool. Consult the manufacturer's instruction manual for correct tool operation.

The readiness code is erased every time the DTC memory is erased or any time the battery is disconnected. If the DTC memory has been erased or the battery is disconnected, a new readiness code must be generated.

Only erase the DTC memory if a DTC has been stored.

General recommendations

Most monitors will complete easier and quicker using a "steady-foot" and "smooth" acceleration during the drive cycle operation.

Operating conditions

For the EVAP monitor test, the coolant temperature and the ambient air temperature must be between 10° C and 35° C with a difference between them no greater than 4° C. The ambient air temperature must not change more than 4° C during the drive cycle procedure (e.g. when driving out of a heated workshop in the winter).

NOTE:

Do not assume that the scan tool ID and engine code are correct if the scan tool communicates. The scan tool does not use the ID to establish communication-the units are automatically identified.

Test requirements

NO DTC in memory.
Switch OFF all electrical and electronic accessories.
Necessary driving speed: 50 - 70 mph.
Drive profile takes approximately 60 - 90 min.

Readiness Drive Cycle Procedure

-- CONNECT: Scan Tool.

Step	Procedure	Result / Action to Take
1	Activate Monitors: START: Engine and idle for 2 - 3 min.	Monitoring Active. Executes Misfire Monitoring.
2	O2 Sensor Monitoring: DRIVE: Vehicle at 45 - 55 mph for a continuous 7 minute period. Avoid stopping.	Executes O2 Sensor Monitoring. Executes Fuel Trim Monitoring. Executes EVAP Monitoring.
3	Fuel Cut-Off Monitoring: ACCELERATE: Vehicle to an engine speed of 5, 000 RPM; lift off the throttle until the engine speed is around 1, 200 RPM.	Fuel Cut-Off Monitoring Ready.
4	Catalyst Monitoring: ACCELERATE: Vehicle smoothly to 60 - 65 mph, cruise at a constant speed for 5 min.	Executes Catalyst Monitoring. Executes O2 Sensor Monitoring. Executes Fuel Trim Monitoring. Executes Misfire Monitoring. Executes EVAP Monitoring.
5	Secondary Air Injection, EVAP Monitoring: DRIVE: Vehicle for 30 - 40 min. at a constant speed of 50 - 70 mph in high gear for 2 min with no coasting.	Executes Secondary Air Injection Monitoring. Executes EVAP Monitoring. Check the status of the readiness code.

-- If any engine monitor fails the drive cycle test. Repeat the drive cycle test until all engine monitors have successfully run through and passed.

NOTE:

When repeating the drive cycle operation for a failed evaporative or thermostat monitor, allow the engine to cool until the coolant temperature and the ambient air temperature are between 10° C and 35° C with a difference between them no greater than 4° C and then repeat the drive cycle operation.

Depending on the scan tool used, the readiness code status may be displayed as complete, passed or OK. At an ambient air temperature < 7° C, the setting of the readiness for the NOx catalytic converter test is delayed. Here the vehicle must be driven considerably longer.

Readiness Codes and Monitoring Completed

If any engine monitor fails the drive cycle test, repeat the drive cycle test until all engine monitors have successfully run through and passed.
If the drive cycle operation fails again:
Check the DTC memory for stored DTCs.
Repair the vehicle if necessary.
Repeat the drive cycle operation until all engine monitors have successfully run through and passed.
Remove the scan tool and switch the ignition off.