Navigating the complexities of vehicle emissions testing can be daunting, especially when dealing with older models like the 2000 Dodge Durango 5.9L. Understanding OBD2 test reports is crucial for ensuring your vehicle passes smog checks and runs efficiently. This guide provides a detailed overview of OBD2 testing, focusing on standards, potential issues, and how they relate to your 2000 Dodge Durango 5.9L.
Understanding OBD2 Systems and Smog Checks
On-Board Diagnostics II (OBD2) systems are sophisticated monitoring systems integrated into vehicles to track the performance of emission control components. Since 1996, OBD2 has been a standard feature in most cars sold in the United States, designed to ensure vehicles meet stringent emission standards. For vehicle owners, especially those with models like the 2000 Dodge Durango 5.9L, understanding OBD2 is key to passing smog inspections, which are mandatory in many regions to regulate air quality.
The OBD2 system works by continuously monitoring various engine and emission control components. It uses sensors to detect malfunctions and, when a problem is detected that could increase emissions, it illuminates the Malfunction Indicator Lamp (MIL), commonly known as the “Check Engine” light. Alongside the MIL, the system stores Diagnostic Trouble Codes (DTCs) which pinpoint the area of the detected issue.
For smog checks, the OBD2 test is a critical component. Testers connect to the vehicle’s OBD2 port to read these DTCs and check the status of “readiness monitors.” These monitors are self-tests that the vehicle’s computer runs to ensure all emission control systems are functioning correctly. A vehicle can fail a smog check if the MIL is illuminated, if there are certain DTCs present, or if too many readiness monitors are not in a “ready” state.
Readiness Monitor Standards for OBD Tests
Readiness monitors are crucial for OBD testing. They indicate whether the vehicle’s emission control systems have been tested and are functioning correctly. For a 2000 Dodge Durango 5.9L, understanding the specific readiness monitor standards is essential for smog check success.
Here’s a breakdown of the readiness monitor standards relevant to a 2000 Dodge Durango 5.9L and similar gasoline vehicles:
| Model Year | Fuel Type | Number of Incomplete Monitors Allowed to Pass OBD Test |
|---|---|---|
| 1996-1999 | Gas | Any one |
| 2000 and newer | Gas | Evaporative system |
For 2000 and newer gasoline vehicles, including your Dodge Durango, the standard allows only the Evaporative System monitor to be incomplete. All other monitors should be in a “ready” state to pass the OBD test portion of a smog check. It’s important to note that the misfire, fuel, and comprehensive component continuous monitors are typically ignored during an OBD test on gasoline vehicles.
Readiness monitors may become “not ready” if the vehicle’s battery has been recently disconnected or if DTCs have been cleared. In such cases, driving the vehicle through a specific “drive cycle” is usually necessary to allow the OBD2 system to rerun these self-tests and set the monitors to “ready.” Sometimes, specific driving conditions are needed to complete certain monitors, and these conditions might be detailed in the vehicle owner’s manual or service literature.
Malfunction Indicator Lamp (MIL) Standards
The Malfunction Indicator Lamp, or MIL, is a primary indicator of your vehicle’s emission system health. For all vehicles with OBD2, including the 2000 Dodge Durango 5.9L, the MIL standards are straightforward:
| Vehicle | Pass/Fail | Standard |
|---|---|---|
| All with OBDII | Pass | MIL illuminates when key on engine off (KOEO). |
| All with OBDII | Pass | MIL turns off when engine running (KOER). |
| All with OBDII | Fail | MIL does not illuminate when key on engine off (KOEO). |
| All with OBDII | Fail | MIL illuminates when engine running (KOER). |
Essentially, the MIL should light up briefly when you turn the key to the “on” position before starting the engine (KOEO) to confirm the bulb is working. Once the engine is running (KOER), the MIL should turn off if no current emission faults are detected. If the MIL stays on while the engine is running, it indicates a problem that needs attention and will likely cause your 2000 Dodge Durango 5.9L to fail a smog check.
Communication Standards for OBD Tests
For a smog check to be performed, the testing equipment must be able to communicate with your vehicle’s OBD2 system. Communication issues can arise from various factors:
- Damaged OBD connector or wiring: Physical damage to the OBD port or associated wiring can prevent proper communication.
- Aftermarket stereo systems: Some aftermarket electronics can interfere with the OBD2 system’s communication lines.
- Computer response issues: In rare cases, the testing tool might receive a response from a different computer module (like the transmission control module) instead of the engine control module, leading to a communication failure.
- Invalid data: Problems within the vehicle’s computer system can sometimes result in the transmission of invalid data, hindering communication.
The communication standards for OBD tests are as follows:
| Vehicle | BAR-97/OIS | Standard |
|---|---|---|
| All with OBDII | BAR-97 | Vehicle communicates with BAR-97. |
| All with OBDII | OIS | Vehicle communicates with OIS and transmits required data. |
For a successful OBD test, your 2000 Dodge Durango 5.9L must communicate effectively with the smog check equipment. This communication involves transmitting essential data, typically including data from OBD addresses: Mode $01 PID $00 (which indicates supported data) and Mode $01 PID $01 (which returns MIL status, DTCs, and monitor status).
Permanent Diagnostic Trouble Code (PDTC) Standards
Permanent Diagnostic Trouble Codes (PDTCs) were introduced to prevent drivers from simply clearing DTCs just before a smog check. PDTCs are similar to regular DTCs but cannot be erased by standard methods such as using a scan tool or disconnecting the battery. They can only be cleared by the OBD2 system itself after it verifies that the underlying issue has been resolved over multiple drive cycles.
However, PDTC standards are not applicable to a 2000 Dodge Durango 5.9L. PDTC checks were implemented for vehicles model year 2010 and newer. For vehicles manufactured between 2000 and 2009, PDTC checks are not part of the smog inspection. Therefore, this is not something you need to worry about for your 2000 Dodge Durango when it comes to smog testing.
| Model Year | BAR-97/OIS | Standard |
|---|---|---|
| 1996-1999 | BAR-97 | Not applicable. |
| 2000-2009 | OIS | Not applicable. |
| 2010 and newer | OIS | Vehicles fail when a PDTC is present. |
Modified Software Standards
Another important aspect of modern smog checks is the check for modified software. Starting July 19, 2021, smog check inspections began including a check for software modifications that are not approved by the California Air Resources Board (CARB). Illegally modified software can cause a vehicle to fail a smog check.
For your 2000 Dodge Durango 5.9L, modified software checks are less likely to be a direct issue unless aftermarket performance chips or ECU tunes have been installed that could affect emissions. However, it’s always best to ensure your vehicle’s software is in its original or CARB-approved configuration to avoid any potential issues during a smog test.
Vehicles identified with non-approved software modifications will fail the smog check. To pass, the vehicle must be restored to an OEM-approved or CARB-approved software configuration before retesting.
Common OBD Test Issues and Your 2000 Dodge Durango 5.9L
While the 2000 Dodge Durango 5.9L is not specifically listed in the original document as having unique OBD test issues, vehicles of this era can still experience common problems that might affect OBD testing and smog check results. The original document does list a range of vehicles with known OBD issues, which can provide insights into potential problems your Durango might face.
Here are some general issues that can affect OBD testing for vehicles similar to your 2000 Dodge Durango 5.9L, drawing from the provided vehicle lists:
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No OBD Communication: Older vehicles, particularly around the 2000s, can sometimes have issues with OBD communication. This can be due to problems with the vehicle’s computer system, wiring, or even software glitches. While the 2000 Dodge Durango isn’t specifically listed for this, communication issues are a general concern for vehicles of this age.
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Readiness Monitor Incompletion: Certain vehicles are known to have difficulty setting specific readiness monitors. For the 2000 Dodge Durango 5.9L (and gasoline vehicles of this era in general), ensuring the Evaporative System monitor is the only one not ready (if any are incomplete) is important. Other monitors like Oxygen Sensor, Catalyst, and EGR (if applicable) should ideally be ready.
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False MIL Illumination: Though less common, some vehicles might have issues where the MIL illuminates without storing relevant DTCs, or due to software sensitivities during OBD tool connection. This is less likely in a 2000 Dodge Durango but is a possible anomaly in some older systems.
To provide a clearer picture, let’s look at excerpts from the original document that are relevant to Dodge vehicles around the 2000 model year:
From Section D: OIS Vehicles of Interest
| Make | Year | Model Engine (L); Fuel Type | Issue | Cause and Possible Remedy | Instruction to Inspector |
|---|---|---|---|---|---|
| Dodge | 1998-2002 | Ram Truck 5.9L (Cummins diesel) [California certified] | Some continuous monitors will not complete. | Vehicle design anomaly. | Test normally. BAR-OIS allows one incomplete continuous monitor. |
| Dodge | 2003 | Dakota, Durango and Ram Trucks with 4.7L engine [California or 50 state certified] | Catalyst monitor readiness status shows as not supported. | Broken vehicle, repair per TSB #18-032-10 with lifetime warranty. | Test normally. OIS ignores unsupported monitors. |
| Dodge | 2003 | Ram Truck 5.9L (Cummins diesel) [California certified] | MIL light is commanded on, but check engine light is not illuminated and no DTCs are stored. | Vehicle design anomaly Recall campaign #K01 for ECM reflash applies to California certified vehicles only. | Test normally. OIS ignores MIL Command if no DTCs are present on this vehicle Advise motorist of Recall Campaign #K01 if the vehicle is California certified. |
An OBD-II port diagram illustrating the pin layout, essential for understanding diagnostic connections.
While these entries are for slightly different Dodge models and engine types, they highlight that design anomalies and monitor readiness issues were present in Dodge vehicles around the 2000s. For a 2000 Dodge Durango 5.9L (gasoline engine), you should primarily be concerned with readiness monitors (ensuring all except Evaporative are ready) and the MIL status.
Troubleshooting Steps for Your 2000 Dodge Durango 5.9L OBD2 Test:
- Check for the Check Engine Light: Ensure the MIL illuminates briefly when the key is turned to the “on” position and turns off when the engine starts. If it stays on, get the DTCs read using an OBD2 scanner.
- OBD2 Scanner Check: Use an OBD2 scanner to read any stored DTCs and check the readiness monitor status. Address any DTCs by diagnosing and repairing the related issues.
- Drive Cycle: If readiness monitors are not set, perform a proper drive cycle for your 2000 Dodge Durango 5.9L. Drive cycle procedures can often be found in your owner’s manual or online repair databases. This typically involves specific driving patterns that help the OBD2 system complete its self-tests.
- Inspect OBD Port: Check the OBD2 port for any physical damage or corrosion that could hinder communication.
- Battery Condition: Ensure your vehicle’s battery is in good condition. A weak battery can sometimes cause communication or electronic issues that might affect OBD testing.
Conclusion: Ensuring OBD2 Readiness for Your 2000 Dodge Durango 5.9L
Passing an OBD2 test is a vital step in smog checking your 2000 Dodge Durango 5.9L. By understanding the OBD2 system, readiness monitor standards, and potential issues, you can better prepare your vehicle for inspection.
Key takeaways for your 2000 Dodge Durango 5.9L:
- Readiness Monitors: Ensure all readiness monitors are set to “ready” except, if necessary, the Evaporative System monitor.
- MIL Status: The Check Engine Light should function correctly—illuminating at KOEO and turning off at KOER. No MIL illumination during KOER is essential for passing.
- Communication: While less common, communication issues can occur. Ensure your OBD2 port is in good condition.
- PDTCs and Modified Software: PDTC checks are not applicable to your 2000 model. Modified software is less likely to be an issue unless aftermarket tuning has been done.
By following these guidelines and addressing any issues proactively, you can increase the chances of your 2000 Dodge Durango 5.9L passing its OBD2 test and smog check, keeping it running cleanly and legally on the road. If you encounter persistent OBD issues or are unsure how to proceed, consulting a certified mechanic specializing in OBD diagnostics is always a wise step. They can provide expert assistance to diagnose and resolve any underlying problems, ensuring your vehicle meets emission standards.
