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Readiness Codes

CAUTION:

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

NOTE:

The alternative is just to have the customer drive the vehicle for 2-3 days. Make sure they include at least one short highway trip, and the Readiness Bits should all reset to "Pass" again.

Readiness code description 

It takes a variety of specific driving conditions to "test" all the systems. It can be done in a short time using a very specific and complicated procedure found in the On Board Diagnostic of the service information for your engine. 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 information 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 

Readiness Drive Cycle Procedure 

-- CONNECT: Scan Tool

Step Procedure Result / Action to Take
1 Activate Monitors:
  • START: Engine and idle for 2 - 3 mins.
  • 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 5000 RPM; lift off the throttle until the engine speed is around 1200 RPM
  • Fuel Cut-Off Monitoring Ready
4 Catalyst Monitoring:
  • ACCELERATE: Vehicle smoothly to 60-65 mph, cruise constantly 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: 30-40 min. at constant speed, 50-70 mph in 5 - 6th gear for 2 mins. No Coasting.
  • Executes Secondary Air Injection Monitoring
  • Executes EVAP Monitoring
  • Check the status of the readiness code
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