The Ford AU Falcon, a popular model in Australia, often presents a confusing scenario when it comes to onboard diagnostics. Many owners and mechanics are puzzled when they encounter an OBD2 connector on their AU Falcon, only to find that standard OBD2 scan tools fail to communicate properly. This article delves into the diagnostic intricacies of the AU Falcon, clarifying whether it truly adheres to the OBD2 standard and how to effectively diagnose issues.
The OBD2 Connector Deception
While the AU Falcon is indeed equipped with an OBD2 connector, it’s not a straightforward OBD2 system in the way many might expect. As observed by users attempting to diagnose their AU Falcons, standard OBD2 scan tools often fail to establish a connection or retrieve meaningful data. This is because, despite having the physical OBD2 port, the AU Falcon, particularly models from the late 90s and early 2000s, may not fully implement the standardized OBD2 protocols.
It’s been suggested that the AU Falcon might utilize an OBD1-style EEC-V (Electronic Engine Control V) setup, employing the OBD2 connector merely as a physical interface. This means that while the connector looks like OBD2, the underlying communication protocols could be different, potentially resembling older, manufacturer-specific diagnostic systems.
One user, with an AU Falcon XR8 built in June 2000, detailed the pin assignments of their OBD2 connector, further highlighting the potential deviation from standard OBD2. These pinouts are worth noting for anyone attempting to diagnose an AU Falcon:
- Pin 1 & 2: Bus +ve
- Pin 3 & 4: Chassis Ground
- Pin 5: Signal Ground
- Pin 6 & 7: ISO Signal tx/rx
- Pin 8, 9, & 10: Bus -ve
- Pin 11, 12, & 13: EEPROM
- Pin 14, 15, & 16: Battery Volts
This pin assignment suggests a more complex setup than a typical OBD2 system, with dedicated pins potentially for specific functionalities like EEPROM access and ISO communication.
Decoding the Pin Assignments
The pinout information provided by the user gives clues about the diagnostic approach required for the AU Falcon. The presence of “ISO Signal tx/rx” pins (6 and 7) suggests the possibility of utilizing the ISO 9141 or ISO 14230 (KWP2000) protocols, which were common in pre-CAN OBD2 systems. Pin 13 being assigned to “EEPROM” is also interesting, potentially indicating a pin used for programming or data writing, possibly with tools like the Ford NGS Star diagnostic unit, which was the standard dealer tool for EEC-V systems in Australia.
Diagnostic Tools and Protocols for AU Falcon
The forum discussion reveals the challenges users faced when trying to diagnose their AU Falcons with generic OBD2 scan tools like ELMSCAN5 and other ELM-based devices. These tools, designed for standard OBD2 protocols, were largely ineffective in retrieving useful information from the AU Falcon.
However, the discussion points towards a few potential avenues for successful diagnostics:
- Ford NGS Star Tester: This dealer-level diagnostic tool was mentioned as being effective with EEC-IV and EEC-V systems, suggesting compatibility with the AU Falcon’s diagnostic system. However, its high cost and limited availability make it impractical for most individual users.
- Siemens K Line Protocol: One expert suggested that the AU Falcon (specifically AU-II models) might adhere to the Siemens K Line protocol. This protocol was used in Australian and Thai-assembled vehicles before the Ford Falcon BA. Tools capable of communicating via the K Line protocol might be more successful in diagnosing AU Falcons.
- SCP (Standard Corporate Protocol): The possibility of the AU Falcon using SCP was also raised. SCP was a Ford-specific protocol used in some models. While less likely than K-Line for AU Falcons based on the forum discussion, it’s another protocol to be aware of if encountering diagnostic issues.
The mention of 4-digit fault codes further hints at a pre-OBD2 or early OBD2 implementation. Standard OBD2 fault codes are typically 5-digit, while older systems often used 2 or 3-digit codes. 4-digit codes could indicate a transitional system or a Ford-specific variation.
Navigating AU Falcon Diagnostics
Diagnosing an AU Falcon requires a different approach compared to standard OBD2 vehicles. Simply plugging in a generic OBD2 scanner might not yield results. Instead, consider these strategies:
- Ford-Specific Scan Tools: Investigate scan tools specifically designed for Ford vehicles, particularly those claiming compatibility with EEC-V systems or older Ford protocols.
- K-Line Compatible Scanners: Explore scan tools that explicitly support the ISO 9141/KWP2000 (K-Line) protocols. These tools might be able to communicate with the AU Falcon’s diagnostic system.
- Professional Diagnostics: If DIY attempts are unsuccessful, seeking professional help from a mechanic familiar with older Ford systems or equipped with advanced diagnostic tools is advisable.
Conclusion: Understanding the AU Falcon OBD2 Reality
In conclusion, while the Ford AU Falcon features an OBD2 connector, it’s crucial to recognize that it may not fully adhere to standard OBD2 protocols. It likely employs a transitional or Ford-specific diagnostic system, possibly based on EEC-V and utilizing protocols like Siemens K Line. Therefore, diagnosing an AU Falcon requires specialized tools and knowledge beyond generic OBD2 scanning. Understanding this distinction is key to effectively troubleshooting and maintaining your AU Falcon.
