Monitors, Trips, Drive Cycles and Readiness Codes
How to Set Readiness CodesMalfunction Indicator Lamp (MIL) Indication (In relation to Readiness Codes)
The vehicle has certain "readiness codes" that are part of the on-board diagnostics for the emissions Systems. If the vehicle's battery has been disconnected or gone dead, if the DTCs have been cleared, or if the PCM has been reset, these readiness codes are reset. In some states, part of the emissions testing is to make sure these codes are set to complete. If all of them are not set to complete, the vehicle may fail the emission test, or the test cannot be finished.
To check if the readiness codes are set to complete, turn the ignition switch ON (II), but do not start the engine. The MIL will come on for 15 - 20 seconds. If it then goes off, the readiness codes are complete. If it flashes five times, one or more readiness codes are not set to complete. To set readiness codes from incomplete to complete, do the procedure for the appropriate code.
Catalytic Converter Monitor and Readiness Code
NOTE:
- Do not turn the ignition switch off during the procedure.
- All readiness codes are cleared when the battery is disconnected, if the DTCs have been cleared, or if the PCM is reset with the HDS.
- Low ambient temperatures or excessive stop-and-go traffic may increase the drive time needed to switch the readiness code from incomplete to complete.
- The readiness code will not switch to complete until all the enable criteria are met.
- If a fault in the secondary HO2S system caused the MIL to come on, the readiness code cannot be set to complete until you correct the fault.
Enable Criteria
- ECT at 158 °F (70 °C) or higher.
- Intake air temperature (IAT) at 20 °F (-7 °C) or higher.
- Vehicle speed sensor (VSS) reads more than 25 mph (40 km/h).
Procedure
1. Connect the HDS to the vehicle's data link connector (DLC), and bring up the READINESS CODES screen for Catalyst in the DTCs MENU.
2. Start the engine.
3. Test-drive the vehicle under stop-and-go conditions with short periods of steady cruise. After about 5 miles (8 km), the readiness code should switch to completed.
4. If the readiness code is still not set to complete, check for a temporary DTC with the HDS. If there is no DTC, one or more of the enable criteria were probably not met; repeat the procedure.
Evaporative Emission (EVAP) Control System Monitor and Readiness Code
NOTE:
- All readiness codes are cleared when the battery is disconnected, if the DTCs have been cleared, or if the PCM is reset with the HDS.
- The enable criteria must be repeated if the intake air temperature (IAT) drops lower than 36°F (2°C) from its valve at engine start up.
Enable Criteria
- At engine start up, ECT and IAT are higher than 32°F (0°C), but lower than 95°F (35°C).
- At engine start up, the ECT and IAT are within 45°F (7°C) of each other.
Procedure
1. Connect the HDS to the vehicle's data link connector (DLC).
2. Start the engine.
3. Test-drive the vehicle under stop-and-go conditions with short periods of steady cruise. After about 2.5 miles (4.0 km), the readiness code should switch from incomplete to complete.
4. If the readiness code is still not set to complete, check for a temporary DTC. If there is no DTC, one or more of the enable criteria were probably not met; repeat the procedure.
HO2S Monitor and Readiness Code
NOTE:
- Do not turn the ignition switch off during the procedure.
- All readiness codes are cleared when the battery is disconnected, if the DTCs have been cleared, or if the PCM is reset with the HDS.
Enable Criteria
ECT at 140 °F (60 °C) or higher.
Procedure
1. Connect the HDS or the scan tool to the vehicle's data link connector (DLC).
2. Start the engine.
3. Test-drive the vehicle under stop-and-go conditions with short periods of steady cruise. During the drive, decelerate (with the throttle fully closed) for 5 seconds. After about 3.5 miles (5.6 km), the readiness code should switch from incomplete to complete.
4. If the readiness code is still not set to complete, check for a temporary DTC. If there is no DTC, the enable criteria was probably not met; repeat the procedure.
HO2S Heater Monitor Readiness Code
NOTE: All readiness codes are cleared when the battery is disconnected, if the DTCs have been cleared, or if the PCM is reset with the HDS.
Procedure
1. Connect the HDS or scan tool to the vehicle's data link connector (DLC)
2. Start the engine, and let it idle for 1 minute. The readiness code should Switch from incomplete to complete.
3. If the readiness code is still not set to complete, check for a temporary DTC. If there is no DTC, repeat the procedure.
Misfire Monitor and Readiness Code
- This readiness code is always set to available because misfiring is continuously monitored.
- Monitoring pauses, and the misfire counter resets, if the vehicle is driven over a rough road.
- Monitoring also pauses, and the misfire counter holds at its current value, if the throttle position changes more than a predetermined value, or if driving conditions fall outside the range of any related enable criteria.
Fuel System Monitor and Readiness Code
- This readiness code is always set to available because the fuel system is continuously monitored during closed loop operation.
- Monitoring pauses when the catalytic converter, EVAP control system, and A/F sensor monitors are active.
- Monitoring also pauses when any related enable criteria are not being met. Monitoring resumes when the enable criteria is again being met.
Comprehensive Component Monitor and Readiness Code
This readiness code is always set to available because the comprehensive component monitor is continuously running whenever the engine is cranking or running.
EGR Monitor and Readiness Code
NOTE:
- Do not turn the ignition switch off during the procedure.
- All readiness codes are cleared when the battery is disconnected, if the DTCs have been cleared, or if the PCM is reset with the HDS.
Enable Criteria
ECT at 176 °F (80 °C) or more.
Procedure
1. Connect the HDS to the vehicle's data link connector (DLC).
2. Start the engine.
3. Drive at a steady speed with the Transmission in D position, 50 - 62 mph (80 - 100 km/h) or above for more than 10 seconds.
4. With the Transmission in D position, decelerate from 62 mph (100 km/h) or above by completely releasing the throttle for at least 5 seconds. If the engine is stopped during this procedure, go to step 3 and do the procedure again.
5. If the readiness code is still set to incomplete, check for a temporary DTC. If there is no DTC, the enable criteria was probably not met; repeat the procedure.