I have been rebuilding a salvage title TJ 2004, and the problem that I have faced is how to pass safety inspection. The issue is like Catch 22 - in order to pass safety inspection and be able to drive, one needs to be able to drive through a drive cycle, so that the computer will run all the monitors to completion.
I researched the web and found the drive cycle documenation and also the description for drive cycle for each monitor in factory manual (2003-2004 4.0 models).
The idea was to place the TJ on 4 jack stands and run the drive cycle in the garage, so that it will cost 0$ to clear the monitors.
Here in Texas, one can have 1 monitor incomplete and pass inspection. Read more here - https://www.dps.texas.gov/section/vehicle-inspection/faq/ready-or-not
By default, after you connect the battery back, you get 4 monitors in not ready state (Monitor Incomplete). These monitors are:
1. Evap sensor
2. Catalyst sensor
3. O2 Heater sensor
4. O2 sensor
After some trials, i was able to bring to ready state 3 monitors (EVAP, 02 heater and O2). I have verified these by disconnecting the battery again, and then doing the process again, so that i dont miss any details.
The setup was TJ 2004 4.0 Auto (No ABS model) on 4 jack stands (2 under front axle, 2 under rear).
- Initially I had the rear jack stands under the rear frame section, but then i found out that the rear axle (Dana 35 in my case) drops too much, and it creates significant vibration when speedometer was around 35MPH - so put the rear jack stands under the axle.
- Some people install jack stands only in the rear, keeping front wheels on the ground. I disagree with this approach, as it completely unsafe. One puts the transfer case into the 4WD by a mistake, and then he gets a disaster.
The precise operation to clear each sensor is below (No check engine lights when the engine is running is a must - if you have check engine light, then the below is not supposed to work, but i did not try). The sequence below is how i have cleared the monitors - first 02 heater, then Evap, then O2 sensor.
a. 02 heater - does not need any driving at all. The vehicle does not need to be on jack stands. No check engine lights when the engine is running.
From the factory manual - this monitor requires a cold start, usually an overnight soak or parked for at least 8 hours without the engine running. The engine coolant temperature must be within 10 degrees of ambient/battery temperature, and the sensed Ambient (outside) Temperature must be be- tween approximately 0° F and 100° F.
The procedure that i followed:
1. Make sure the gas tank is slightly under 75% full and slighly above 50% full. It possible that it will work fine with other gas tank levels, but i did not experiment with them.
2. Let the vehicle cool down for at least 10 hours, so that the engine temperatures will get into the 10 degree delta from the ambient air temperature.
3. Make sure that the ambient air temperature is under 90 degrees (which is not a problem even here in Texas). It is possible that it will run with higher temperatures, but i did not try it.
4. Start the engine in when transmission in Park, and just idle for 5 minutes. Keep AC, lights and everything else off. Don't use steering wheel as well.
5. Shut the engine, remove the key.
6. Leave it it alone for 20 minutes
7. Come back and run the scan with scan tool, and verify that the monitor is ready.
b. Evap sensor - does not need any driving at all. The vehicle does not need to be on jack stands. Extremely sensitive to air temperature, so if you are in Texas in the summer, you have a problem. Mine is equipped with Leak detection Pump, so it is applicable for it.
From the factory manual:
Page 4 in general information section - This monitor requires a cold start, usually an overnight soak or parked for at least 8 hours without the engine running. The engine coolant temperature must be within 10 degrees of ambient/battery temperature, and the sensed Ambient (outside) Temperature must be be- tween approximately 40° F and 90° F.
Page 7 in general information section- Conditions on Evap monitor running - Cold start: with ambient temperature (obtained from modeling the inlet air temperature sensor on passenger vehicles and the battery temperature sensor on Jeep & truck vehicles) between 4°C (40°F) and 32°C (90°F) for 0.040 leak. Be- tween 4°C (40°F) and 29°C (85°F) for 0.020 leak. Engine coolant temperature within: -12° to -8°C (10° to 18°F) of battery/ambient. Battery voltage between 10 and 15 volts. If battery voltage drops below 10 volts for more than 5 seconds during engine cranking, the EVAP leak detection test will not run. Low fuel warning light off (fuel level must be between 15% and 85%). MAP sensor reading 22 in Hg or above (This is the manifold absolute pressure, not vacuum). No engine stall during test.
The procedure:
1. Make sure the gas tank is slightly under 75% full and slighly above 50% full. It possible that it will work fine with other gas tank levels, but i did not experiment with them.
2. Let the vehicle cool down for at least 10 hours, so that the engine temperatures will get into the 10 degree delta from the ambient air temperature.
3. Make sure that the ambient air temperature is around 75 degrees (which is a problem here in Texas in summer). It is possible that it will run with higher temperatures, but it did not work well for me. I had to put it outside of the garage, and wait 3-4 days till the air temperature was low enough at around 1AM (reached 75 degrees). I tried it every night, and it failed, till the coldest (I mean like Texas coldest) night with 75 degree at 1AM, where it worked. It is possible that the upper thermal boundary depends on tear and wear on the system, so it might work for you at 85C as well, if it is in much better shape.
4. Start the engine in when transmission in Park, and just idle for 5 minutes. Keep AC, lights and everything else off. Don't use steering wheel as well.
5. Shut the engine, remove the key.
6. Leave it it alone for 20 minutes
7. Come back and run the scan with scan tool, and verify that the monitor is ready.
Notes - i have found this while searching the web. - https://img.neons.org/AGN/chrysler_drive_cycle.pdf. It states that the vehicle needs to be driven to run the evap, which i think that contradicts the factory manual, and my own experience. No need for driving for this one.
c. O2 Sensor - Needs driving, so 4 jack stands are must. Does not seem like it is sensitive to air temperature, as i did it in my garage when it was really hot.
From the factory manual - The vehicle will need to be driven for a period of time and brought to a stop for a short period of time with the Automatic Transmission left in Drive. The O2S Monitor will not run in Park or Neutral on an Automatic Transmission equipped vehicle.
The procedure:
1. Make sure the gas tank is slightly under 75% full and slighly above 50% full. It possible that it will work fine with other gas tank levels, but i did not experiment with them.
2. Let the vehicle cool down for at least 10 hours, so that the engine temperatures will get into the 10 degree delta from the ambient air temperature.
3. Temperature of air - it does not seem like it matters. I was running inside my garage, with open garage door, and it was really hot, like 95+ degree hot.
4. Start the engine in when transmission in Park, and just idle for 5 minutes. Keep AC, lights and everything else off. Don't use steering wheel as well. Shut down the overdrive before starting the engine, as it will be hard to keep the precise speeds with overdive on.
5. Press the brakes, put into Drive, and accelerate to ~ 30MPH. Stay at that speed around 2 minutes. Dont use cruise control.
6. Release the gas pedal, and slowly brake to 0MPH. Keep transmission in drive and idle for 30 seconds.
7. Smoothly accelerate to a speed around 35MPH. Stay there for 2 minutes.
8. Release the gas pedal, and slowly brake to 0MPH. Keep transmission in drive and idle for 30 seconds. Dont use cruise control.
9. Smoothly accelerate to a speed around 35MPH. Stay there for 2 minutes.
10. Release the gas pedal, and slowly brake to 0MPH. Keep transmission in drive and idle for 30 seconds. Dont use cruise control.
11. Smoothly accelerate to a speed around 35MPH. Stay there for 2 minutes.
12. Release the gas pedal, and slowly brake to 0MPH. Keep transmission in drive and idle for 30 seconds. Dont use cruise control
13. Smoothly accelerate to a speed around 35MPH. Stay there for 2 minutes.
14. Release the gas pedal, and slowly brake to 0MPH. Keep transmission in drive and idle for 30 seconds. Dont use cruise control.
15. Smoothly accelerate to a speed around 35MPH. Stay there for 2 minutes.
16. Release the gas pedal, and slowly brake to 0MPH. Put transmission into park.
17. Shut down the engine, remove the key.
18. Leave it it alone for 20 minutes
19. Come back and run the scan with scan tool, and verify that the monitor is ready.
I have followed through the process described above, at least couple of times, to make sure that all is correct.
My problem is that i not able to figure out how to cause the Catalyst monitor to clear. If anyone knows, please (really asking as I want to know), please reply here.
I hope this information will be useful for fellow Jeepers.
I researched the web and found the drive cycle documenation and also the description for drive cycle for each monitor in factory manual (2003-2004 4.0 models).
The idea was to place the TJ on 4 jack stands and run the drive cycle in the garage, so that it will cost 0$ to clear the monitors.
Here in Texas, one can have 1 monitor incomplete and pass inspection. Read more here - https://www.dps.texas.gov/section/vehicle-inspection/faq/ready-or-not
By default, after you connect the battery back, you get 4 monitors in not ready state (Monitor Incomplete). These monitors are:
1. Evap sensor
2. Catalyst sensor
3. O2 Heater sensor
4. O2 sensor
After some trials, i was able to bring to ready state 3 monitors (EVAP, 02 heater and O2). I have verified these by disconnecting the battery again, and then doing the process again, so that i dont miss any details.
The setup was TJ 2004 4.0 Auto (No ABS model) on 4 jack stands (2 under front axle, 2 under rear).
- Initially I had the rear jack stands under the rear frame section, but then i found out that the rear axle (Dana 35 in my case) drops too much, and it creates significant vibration when speedometer was around 35MPH - so put the rear jack stands under the axle.
- Some people install jack stands only in the rear, keeping front wheels on the ground. I disagree with this approach, as it completely unsafe. One puts the transfer case into the 4WD by a mistake, and then he gets a disaster.
The precise operation to clear each sensor is below (No check engine lights when the engine is running is a must - if you have check engine light, then the below is not supposed to work, but i did not try). The sequence below is how i have cleared the monitors - first 02 heater, then Evap, then O2 sensor.
a. 02 heater - does not need any driving at all. The vehicle does not need to be on jack stands. No check engine lights when the engine is running.
From the factory manual - this monitor requires a cold start, usually an overnight soak or parked for at least 8 hours without the engine running. The engine coolant temperature must be within 10 degrees of ambient/battery temperature, and the sensed Ambient (outside) Temperature must be be- tween approximately 0° F and 100° F.
The procedure that i followed:
1. Make sure the gas tank is slightly under 75% full and slighly above 50% full. It possible that it will work fine with other gas tank levels, but i did not experiment with them.
2. Let the vehicle cool down for at least 10 hours, so that the engine temperatures will get into the 10 degree delta from the ambient air temperature.
3. Make sure that the ambient air temperature is under 90 degrees (which is not a problem even here in Texas). It is possible that it will run with higher temperatures, but i did not try it.
4. Start the engine in when transmission in Park, and just idle for 5 minutes. Keep AC, lights and everything else off. Don't use steering wheel as well.
5. Shut the engine, remove the key.
6. Leave it it alone for 20 minutes
7. Come back and run the scan with scan tool, and verify that the monitor is ready.
b. Evap sensor - does not need any driving at all. The vehicle does not need to be on jack stands. Extremely sensitive to air temperature, so if you are in Texas in the summer, you have a problem. Mine is equipped with Leak detection Pump, so it is applicable for it.
From the factory manual:
Page 4 in general information section - This monitor requires a cold start, usually an overnight soak or parked for at least 8 hours without the engine running. The engine coolant temperature must be within 10 degrees of ambient/battery temperature, and the sensed Ambient (outside) Temperature must be be- tween approximately 40° F and 90° F.
Page 7 in general information section- Conditions on Evap monitor running - Cold start: with ambient temperature (obtained from modeling the inlet air temperature sensor on passenger vehicles and the battery temperature sensor on Jeep & truck vehicles) between 4°C (40°F) and 32°C (90°F) for 0.040 leak. Be- tween 4°C (40°F) and 29°C (85°F) for 0.020 leak. Engine coolant temperature within: -12° to -8°C (10° to 18°F) of battery/ambient. Battery voltage between 10 and 15 volts. If battery voltage drops below 10 volts for more than 5 seconds during engine cranking, the EVAP leak detection test will not run. Low fuel warning light off (fuel level must be between 15% and 85%). MAP sensor reading 22 in Hg or above (This is the manifold absolute pressure, not vacuum). No engine stall during test.
The procedure:
1. Make sure the gas tank is slightly under 75% full and slighly above 50% full. It possible that it will work fine with other gas tank levels, but i did not experiment with them.
2. Let the vehicle cool down for at least 10 hours, so that the engine temperatures will get into the 10 degree delta from the ambient air temperature.
3. Make sure that the ambient air temperature is around 75 degrees (which is a problem here in Texas in summer). It is possible that it will run with higher temperatures, but it did not work well for me. I had to put it outside of the garage, and wait 3-4 days till the air temperature was low enough at around 1AM (reached 75 degrees). I tried it every night, and it failed, till the coldest (I mean like Texas coldest) night with 75 degree at 1AM, where it worked. It is possible that the upper thermal boundary depends on tear and wear on the system, so it might work for you at 85C as well, if it is in much better shape.
4. Start the engine in when transmission in Park, and just idle for 5 minutes. Keep AC, lights and everything else off. Don't use steering wheel as well.
5. Shut the engine, remove the key.
6. Leave it it alone for 20 minutes
7. Come back and run the scan with scan tool, and verify that the monitor is ready.
Notes - i have found this while searching the web. - https://img.neons.org/AGN/chrysler_drive_cycle.pdf. It states that the vehicle needs to be driven to run the evap, which i think that contradicts the factory manual, and my own experience. No need for driving for this one.
c. O2 Sensor - Needs driving, so 4 jack stands are must. Does not seem like it is sensitive to air temperature, as i did it in my garage when it was really hot.
From the factory manual - The vehicle will need to be driven for a period of time and brought to a stop for a short period of time with the Automatic Transmission left in Drive. The O2S Monitor will not run in Park or Neutral on an Automatic Transmission equipped vehicle.
The procedure:
1. Make sure the gas tank is slightly under 75% full and slighly above 50% full. It possible that it will work fine with other gas tank levels, but i did not experiment with them.
2. Let the vehicle cool down for at least 10 hours, so that the engine temperatures will get into the 10 degree delta from the ambient air temperature.
3. Temperature of air - it does not seem like it matters. I was running inside my garage, with open garage door, and it was really hot, like 95+ degree hot.
4. Start the engine in when transmission in Park, and just idle for 5 minutes. Keep AC, lights and everything else off. Don't use steering wheel as well. Shut down the overdrive before starting the engine, as it will be hard to keep the precise speeds with overdive on.
5. Press the brakes, put into Drive, and accelerate to ~ 30MPH. Stay at that speed around 2 minutes. Dont use cruise control.
6. Release the gas pedal, and slowly brake to 0MPH. Keep transmission in drive and idle for 30 seconds.
7. Smoothly accelerate to a speed around 35MPH. Stay there for 2 minutes.
8. Release the gas pedal, and slowly brake to 0MPH. Keep transmission in drive and idle for 30 seconds. Dont use cruise control.
9. Smoothly accelerate to a speed around 35MPH. Stay there for 2 minutes.
10. Release the gas pedal, and slowly brake to 0MPH. Keep transmission in drive and idle for 30 seconds. Dont use cruise control.
11. Smoothly accelerate to a speed around 35MPH. Stay there for 2 minutes.
12. Release the gas pedal, and slowly brake to 0MPH. Keep transmission in drive and idle for 30 seconds. Dont use cruise control
13. Smoothly accelerate to a speed around 35MPH. Stay there for 2 minutes.
14. Release the gas pedal, and slowly brake to 0MPH. Keep transmission in drive and idle for 30 seconds. Dont use cruise control.
15. Smoothly accelerate to a speed around 35MPH. Stay there for 2 minutes.
16. Release the gas pedal, and slowly brake to 0MPH. Put transmission into park.
17. Shut down the engine, remove the key.
18. Leave it it alone for 20 minutes
19. Come back and run the scan with scan tool, and verify that the monitor is ready.
I have followed through the process described above, at least couple of times, to make sure that all is correct.
My problem is that i not able to figure out how to cause the Catalyst monitor to clear. If anyone knows, please (really asking as I want to know), please reply here.
I hope this information will be useful for fellow Jeepers.
