Monitors, Trips, Drive Cycles and Readiness Codes

Malfunction 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, these codes are erased. In some states, part of the emissions testing is to make sure these codes are set. If all of them are not set, the test cannot be completed.

To check if the readiness codes are set, 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 set. If it blinks several times, the readiness codes are not set completely. To reset each code, drive the vehicle or run the engine as described in the following procedures.

Catalytic Converter

NOTE:
- Do not turn the ignition switch OFF.
- When the battery negative cable is disconnected, all readiness codes are cleared.

Required condition:
Ambient temperature between 20 - 95 °F (-7 - 35 °C).
1. Connect the scan tool to the Data Link Connector (DLC).
2. Start the engine. Hold it at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on.
3. Drive for about 10 minutes without stopping on a highway or freeway. Your speed can vary.
4. With the transmission in D5 position, drive at a steady speed between 50 - 62 mph (80 - 100 km/h) for 30 seconds.
5. Do step 4 three times. Between each procedure, close the throttle completely for 1 - 2 seconds. If the engine is stopped during this procedure, go to step 3 and do the procedure again.
6. Check for the readiness code with the scan tool.

EGR Monitor

NOTE:
- Do not turn the ignition switch OFF.
- When the battery negative cable is disconnected, all readiness codes are cleared.

1. Connect the scan tool to the Data Link Connector (DLC).
2. Start the engine, and hold it at 3,000 rpm with no load (in Park and neutral) until the radiator fan comes on.
3. Drive at a steady speed with the transmission in D5- position between 50 - 62 mph (80 - 100 km/h) for more than 10 seconds.
4. With the transmission in D5 position, decelerate from 62 mph (100 km/h) 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. Check for the readiness code with the scan tool.

EVAP Leak Monitor

NOTE:
- When the battery negative cable is disconnected, all readiness codes are cleared.
- If the engine is stopped while doing the procedure between step 6 and 16, do this procedure from step 1 again.

1. Make sure the gasoline level is 60 - 90 % of fuel tank capacity (not full).
2. Turn the ignition switch OFF.
3. Let the vehicle sit more than 8 hours.
4. Make sure the outside temperature is 20 - 95 °F (-7 - 35 °C).
5. Connect the scan tool to the Data Link Connector(DLC).
6. Start the engine and drive for about 15 minutes.
7. Keep the vehicle at a steady speed between 50 - 70 mph (80 - 114 km/h), without moving the accelerator pedal, for about 1 minute.
8. Stop the vehicle (do not stop engine).
9. Replace steps 7 and 8 two more times.
10. Check for the readiness code with the scan tool. If the readiness code does not set, go to step 11.
11. When ambient temperature is less than 32 °F (0 °C), hold the engine at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on.
12. When ambient temperature is more than 86 °F (30 °C), remove the fuel fill cap, then install the fuel fill cap.
13. After step 12, drive for about 20 minutes on a freeway.
14. Keep the vehicle at a steady speed between 50 - 70 mph (80 - 114 km/h), without moving the accelerator pedal, for about 1 minute.
15. Stop the vehicle (do not stop the engine).
16. Repeat steps 14 and 15 two more times.
17. Check for the readiness code with the scan tool.

HO2S Monitor

NOTE:
- Do not turn the ignition switch OFF.
- When the battery negative cable is disconnected, all readiness codes are cleared.

Required condition: Ambient temperature between 20 - 95 °F (-7 - 35 °C).

1. Connect the scan tool to the Data Link Connector (DLC).
2. Start the engine, and hold it at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on.
3. Let the engine idle for 5 seconds.
4. Drive at a steady speed between 50 - 62 mph (80 - 100 km/h) for about 2 minutes.
5. With the transmission in D5 position, decelerate from 62 mph (100 km/h) by completely releasing the throttle with complete closed for at least 5 seconds. If the engine is stopped during this procedure, go to step 4 and do the procedure again.
6. Check for the readiness code with the scan tool.

HO2S Heater Monitor

NOTE: When the battery negative cable is disconnected, all readiness codes are cleared.

1. Connect the scan tool to the Data Link Connector (DLC).
2. Start the engine, and let the engine idle for 10 minutes.
3. Check for the readiness code with the scan tool.