Navigating the world of vehicle maintenance can often feel like deciphering a complex code, especially when it comes to emissions testing. For owners of a 2000 Dodge Durango 5.9L, understanding the smog test and its On-Board Diagnostic (OBD2) report is crucial for ensuring your vehicle meets environmental standards and stays legally compliant. This guide breaks down what you need to know about your 2000 Dodge Durango’s smog test OBD2 report, ensuring you’re well-informed and prepared.
Understanding the Basics of OBD2 Smog Testing
To properly interpret your 2000 Dodge Durango 5.9L smog test OBD2 report, it’s essential to grasp the fundamentals of OBD2 systems and smog checks.
What is OBD2?
OBD2, or On-Board Diagnostics II, is a standardized system in vehicles since 1996, designed to monitor the performance of an engine and its emission control systems. This system includes a computer that detects malfunctions, stores Diagnostic Trouble Codes (DTCs), and illuminates the Malfunction Indicator Lamp (MIL), commonly known as the “Check Engine” light, on your dashboard when an issue is detected. For a 2000 Dodge Durango 5.9L, the OBD2 system is pivotal for diagnosing and maintaining engine health and emission control efficiency.
The Smog Check and OBD2
Smog checks, or emissions tests, are mandated in many regions to ensure vehicles comply with air quality regulations. The OBD2 test portion of a smog check is a critical component, where your 2000 Dodge Durango 5.9L’s computer system is scanned for emission-related issues. This test assesses several key parameters:
- Readiness Monitors: These are system self-tests that confirm whether emission control systems are functioning correctly.
- Malfunction Indicator Lamp (MIL) Status: Checks if the “Check Engine” light is on or has been triggered, indicating potential problems.
- Communication: Verifies that the smog check equipment can properly communicate with your vehicle’s OBD2 system.
- Permanent Diagnostic Trouble Codes (PDTCs): In newer vehicles (2010 and newer, though this doesn’t directly apply to a 2000 Durango for PDTC failure), these are DTCs that cannot be cleared by simply resetting the system and require the underlying issue to be resolved.
Why is OBD2 Testing Important for a 2000 Dodge Durango 5.9L?
For your 2000 Dodge Durango 5.9L, OBD2 testing is not just about passing a smog check; it’s about ensuring your vehicle operates cleanly and efficiently. A properly functioning emission control system is vital for reducing harmful pollutants and maintaining engine performance. The OBD2 system helps identify potential issues early, allowing for timely repairs that can prevent more significant problems and ensure your Durango remains environmentally responsible.
Key Components of a 2000 Dodge Durango 5.9L OBD2 Smog Test Report
Understanding the different sections of your 2000 Dodge Durango 5.9L OBD2 smog test report is key to interpreting the results. Let’s break down the main components.
Readiness Monitors: Ensuring Your Durango is Ready
Readiness monitors are diagnostic tests that your 2000 Dodge Durango 5.9L’s OBD2 system performs to check if various emission control systems are functioning correctly. These monitors need to be in a “ready” state for a vehicle to pass the OBD2 portion of a smog test. However, some monitors are allowed to be “not ready” depending on the vehicle’s model year and fuel type.
For a 2000 and newer gasoline vehicle, such as your 2000 Dodge Durango 5.9L, the standard allows for only the Evaporative system monitor to be incomplete and still pass the OBD test. All other applicable monitors should be in a “ready” state. The original document specifies:
| Model Year | Fuel Type | Number of Incomplete Monitors Allowed to Pass OBD Test¹ |
|---|---|---|
| 1996-1999 | Gas² | Any one³ |
| 2000 and newer | Gas² | Evaporative system³ |
| 1998-2006 | Diesel | Zero |
| 2007 and newer | Diesel | Particulate Filter and Non-Methane HydroCarbon (NMHC)⁴ |
¹ Implemented May 4, 2015.
² “Gas” includes gasoline, propane, natural gas (CNG, LNG, LPG).
³ The misfire, fuel, and comprehensive component continuous monitors are ignored during an OBD test on “gas” vehicles.
⁴ Implemented July 5, 2023.
This means for your 2000 Dodge Durango 5.9L, you can pass the OBD test with the Evaporative System monitor incomplete, but all other relevant monitors must be ready. Common monitors include:
- Catalyst Monitor: Checks the efficiency of the catalytic converter.
- Evaporative System Monitor: Tests for fuel vapor leaks in the evaporative emissions system.
- Oxygen Sensor Monitor: Evaluates the performance of the oxygen sensors.
- Oxygen Sensor Heater Monitor: Checks the functionality of the oxygen sensor heaters.
- EGR System Monitor: (Exhaust Gas Recirculation) – Verifies the operation of the EGR system, which reduces NOx emissions.
- Secondary Air System Monitor: Tests the secondary air injection system (if equipped), which helps reduce cold-start emissions.
- Fuel System Monitor: Checks the fuel delivery system for proper operation.
- Comprehensive Components Monitor: Monitors various engine components for malfunctions.
If your 2000 Dodge Durango 5.9L fails the readiness monitor portion, it means one or more required monitors are not in a “ready” state (excluding the evaporative system monitor, which is allowed to be incomplete). This could be due to various reasons, such as recent battery disconnection, fault codes that were recently cleared, or underlying issues preventing the monitors from completing their tests.
Malfunction Indicator Lamp (MIL): Is Your Check Engine Light Telling a Story?
The Malfunction Indicator Lamp (MIL), or “Check Engine” light, is a critical indicator of your 2000 Dodge Durango 5.9L’s emission system status. The smog test checks the MIL in two key states: Key On Engine Off (KOEO) and Key On Engine Running (KOER). According to the original reference:
| 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). |
For a passing smog test, your 2000 Dodge Durango 5.9L should exhibit the following MIL behavior:
- Pass: The MIL should turn ON when the key is turned to the “ON” position but the engine is OFF (KOEO). This confirms the MIL is functional.
- Pass: The MIL should turn OFF once the engine is started and running (KOER), provided there are no active emission-related faults.
- Fail: If the MIL does not illuminate during KOEO, it indicates a problem with the MIL system itself, which is a failure.
- Fail: If the MIL remains illuminated during KOER, it signifies that the OBD2 system has detected one or more emission-related faults, leading to a failure.
If your 2000 Dodge Durango 5.9L fails the MIL test, it means there’s an active emission-related issue that needs to be diagnosed and repaired before it can pass a smog check. DTCs stored in the OBD2 system will need to be retrieved to pinpoint the problem.
Communication Standards: Connecting with Your Durango’s Computer
For a successful OBD2 smog test, the testing equipment must be able to establish reliable communication with your 2000 Dodge Durango 5.9L’s computer system. Communication issues can arise from several factors, including problems with the OBD2 port, wiring, or the vehicle’s computer itself.
The communication standards for OBD tests are:
| 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.¹ |
¹ Required data typically means data from OBD addresses: Mode $01 PID $00, Mode $01 PID $01. Mode $01 PID $00 returns what data is supported on the vehicle. Mode $01 PID $01 returns MIL status, diagnostic trouble codes (DTCs), and monitor status.
A communication failure during a smog test of your 2000 Dodge Durango 5.9L can result in a failed test. This could stem from:
- Damaged OBD Connector or Wiring: Physical damage to the OBD port or associated wiring can prevent proper communication.
- Aftermarket Stereo or Accessories: Improperly installed aftermarket electronics can sometimes interfere with the OBD2 system.
- Computer Issues: In rare cases, issues with the vehicle’s engine computer (ECM) or transmission computer (TCM) can cause communication problems.
- Invalid Data: If the vehicle transmits incorrect or invalid data, it can also lead to a communication failure.
If your 2000 Dodge Durango 5.9L fails due to a communication issue, it’s essential to diagnose the cause of the communication breakdown before re-attempting the smog test.
Permanent Diagnostic Trouble Codes (PDTCs): Codes That Stick Around
Permanent Diagnostic Trouble Codes (PDTCs) were introduced in later OBD2 systems and became relevant for smog checks in 2010 and newer vehicles concerning PDTC failures. While the original document notes PDTC checks are not applicable for 2000-2009 vehicles in terms of failure standards during a smog test, understanding PDTCs is still beneficial for overall OBD2 system comprehension.
| Model Year | BAR-97/OIS | Standard |
|---|---|---|
| 1996-1999 | BAR-97 | Not applicable. |
| 2000-2009 | OIS | Not applicable. |
| 2010 and newer ¹ | OIS | Vehicles fail when a PDTC is present. ²,³,⁴,⁵ |
¹ Some 2010 vehicles do not support PDTC. Those without support for PDTC will not be subject to the PDTC check.
² A vehicle with a PDTC stored will fail the PDTC check regardless of whether the MIL is commanded ON or OFF.
³ PDTC presence will be ignored if the vehicle has completed at least 15 warm-up cycles and been driven at least 200 miles since its OBD information was last cleared (as determined by Mode $01 PID $30 and $31).
⁴ BAR is aware of some vehicles that have trouble properly clearing certain PDTCs. BAR is working with the California Air Resources Board (CARB) to ensure that known problematic vehicles are addressed by vehicle manufacturers. Until then, these codes will be ignored by BAR-OIS. For more information, see Permanent Diagnostic Trouble Code Vehicles of Interest.
⁵ Vehicle manufacturers have issued extended warranties, recalls and repair campaigns for some vehicles that have trouble properly clearing PDTCs. These vehicles are listed under Permanent Diagnostic Trouble Code Vehicles of Interest. When one of these vehicles fails for the PDTC, please refer the motorist to the dealer for covered repairs.
PDTCs are essentially DTCs that cannot be cleared by simply using a scan tool or disconnecting the battery. They are designed to ensure that a vehicle has properly addressed an emission issue before passing a smog test. PDTCs will only clear themselves once the OBD2 system verifies that the fault condition is no longer present over multiple drive cycles.
Although PDTC failures are not a direct concern for passing a smog test on your 2000 Dodge Durango 5.9L according to the table, if you encounter PDTCs during diagnostics, it indicates a past emission issue that was significant enough to set a permanent code. Addressing the root cause of any PDTCs is still recommended for maintaining your Durango’s emission system health, even if it doesn’t directly cause a smog test failure due to PDTC presence itself.
Common OBD2 Smog Test Failure Points for Vehicles Like the 2000 Dodge Durango 5.9L
While the original document provides a comprehensive list of “Vehicles of Interest” with known OBD test issues, it does not specifically list the 2000 Dodge Durango 5.9L as having unique, pre-identified problems in those sections. However, understanding general failure points for vehicles of this era can be beneficial. Common OBD2 smog test failure points for vehicles around the year 2000, including models like the Dodge Durango, often relate to:
Communication Failures
Although not specifically listed for Durango in the document, communication issues can still occur due to:
- OBD-II Port Damage: Physical damage to the OBD-II port can prevent proper connection with testing equipment.
- Wiring Problems: Faulty wiring to the OBD-II port or within the vehicle’s diagnostic system.
- Module Issues: Problems with the ECM or other control modules could, in theory, lead to communication failures, though this is less common.
Readiness Monitor Issues
- Incomplete Monitors: As mentioned earlier, for 2000 and newer gasoline vehicles, only the evaporative system monitor can be incomplete. Other monitors like Catalyst, Oxygen Sensor, EGR, etc., must be ready. Failure to complete these can be due to:
- Drive Cycle Not Completed: Many monitors require specific driving conditions (drive cycles) to run and complete. If these conditions haven’t been met since the last code clearing or battery disconnection, monitors may be incomplete.
- Underlying System Faults: A genuine issue in an emission system (e.g., faulty oxygen sensor, EGR valve problem) can prevent the corresponding monitor from setting to “ready”.
- False “Not Ready” Readings: In some rare cases, software glitches or sensor inaccuracies might falsely report a monitor as “not ready.”
MIL On Failures
- Active DTCs: If the “Check Engine” light is on (MIL illuminated during KOER), it means the OBD2 system has detected one or more emission-related DTCs. Common causes include:
- Catalytic Converter Efficiency Issues: DTCs related to catalyst efficiency (e.g., P0420) are frequent in older vehicles.
- Oxygen Sensor Problems: Faulty or degraded oxygen sensors can trigger MIL illumination.
- Evaporative Emission System Leaks: EVAP system leaks (small or large) are common causes for DTCs.
- EGR System Malfunctions: EGR valve or system issues can also trigger codes and MIL.
- Misfires: Engine misfires, if severe enough to affect emissions, will turn on the MIL.
PDTC Failures (General Understanding, Not Directly Applicable for 2000 Durango Smog Failure)
Although PDTC failures are not a standard for vehicles of this age for smog failure as per the provided tables, understanding them in a general context is helpful. If, during any diagnostic process, PDTCs are present on a 2000 Durango, it typically indicates a previously detected emission fault that was significant. While not causing a smog failure due to PDTC presence itself on a 2000 model, it signals a past issue that was serious enough to set a permanent code and warrants investigation into the underlying cause for overall vehicle health.
Passing Your 2000 Dodge Durango 5.9L Smog Test: Tips and Best Practices
To increase the chances of your 2000 Dodge Durango 5.9L passing its smog test, consider these tips and best practices:
Ensuring Readiness Monitors are Set
- Complete a Drive Cycle: If your vehicle has recently had its battery disconnected or DTCs cleared, you’ll likely need to perform a drive cycle to set the readiness monitors. Drive cycles involve specific driving patterns that help the OBD2 system run its self-tests. While specific drive cycles for a 2000 Dodge Durango 5.9L can be found in the service manual, a general OBDII drive cycle often includes a combination of highway and city driving, accelerations, decelerations, and periods of idling.
- Allow Sufficient Driving Time: Give your Durango ample time to complete its monitors under normal driving conditions. Sometimes, it can take several days of regular driving for all monitors to become ready.
- Avoid Aggressive Driving: Smooth, moderate driving is generally more conducive to setting readiness monitors than aggressive acceleration and braking.
Addressing MIL Issues
- Diagnose and Repair DTCs: If your “Check Engine” light is on, have the DTCs diagnosed by a qualified mechanic. Repair any identified issues before the smog test. Common repairs might involve replacing oxygen sensors, fixing EVAP leaks, or addressing catalytic converter problems.
- Pre-Smog Check Inspection: Consider a pre-smog check inspection at a repair shop. They can check your Durango’s OBD2 system, read DTCs, and assess readiness monitor status, giving you an idea of potential issues before the official test.
- Don’t Just Clear Codes: Simply clearing DTCs right before a smog test is usually not effective and can even cause a failure due to unset readiness monitors. Address the underlying problems instead of just masking the symptoms.
Checking for Communication Problems
- Inspect the OBD-II Port: Before the test, visually inspect your Durango’s OBD-II port for any damage or obstructions. Ensure it’s clean and free from debris.
- Ensure No Aftermarket Interference: If you have recently installed any aftermarket electronics, temporarily disconnect them to rule out any potential interference with the OBD2 system during the smog test.
- Professional Diagnostic Check: If you suspect a communication issue, have a professional technician diagnose the OBD-II system, wiring, and vehicle computer for any faults.
Conclusion
Understanding your 2000 Dodge Durango 5.9L smog test OBD2 report is essential for vehicle maintenance and compliance. By knowing the key components—Readiness Monitors, MIL status, Communication, and the general context of DTCs and PDTCs—you can better prepare for smog checks and maintain your vehicle’s emission system effectively. While specific issues for the 2000 Durango 5.9L aren’t highlighted in the original reference document, general OBD2 test principles and common failure points for vehicles of that era apply. By following best practices and addressing any identified problems, you can ensure your 2000 Dodge Durango 5.9L meets smog test standards and continues to operate cleanly and efficiently.
