For Volvo 850 owners, especially those with models from 1996 and 1997, understanding how to accurately read vehicle mileage is crucial for maintenance and diagnostics. There’s a common misconception regarding the effectiveness of Light Led Obdii Readers for this task, particularly when attempting to use them on pin 7 of the OBDII port. It’s important to clarify that a flashing LED tool is not capable of reading the mileage on ’96-’97 Volvo 850 models through pin 7.
The reason lies in the technical specifications of the vehicle’s communication system. Mileage data on these Volvo 850s is accessed from the COMBI instrument cluster via pin 7, operating at a high-speed 10400 baud rate. This data transmission speed is far too rapid for a flashing LED OBDII reader to interpret. These basic LED tools simply cannot process information at that velocity, rendering them ineffective for mileage reading in this specific scenario.
Instead, a more sophisticated tool is required: an ELM327 device. To correctly communicate with the ’96-’97 Volvo 850 and retrieve mileage data, the ELM327 must be properly configured to utilize the KWPD3B0 protocol. This Volvo-specific protocol, similar to ISO 9141-2, employs a 5-baud initialization and a 10400-baud normal communication speed. This protocol is essential for interacting with various systems within these Volvo models, including the COMBI, SRS, ABS, AW 50-42 transmission, power seats, Motronic 4.4 engine management, and immobilizer.
While light LED OBDII readers are unsuitable for mileage reading on pin 7, they do have applications within the ’96-’97 850’s OBDII system. These tools are designed for use with other systems via different pins: Motronic 4.3 on pin 3, ECC (Electronic Climate Control) on pin 6, and Cruise Control on pin 13. Therefore, while not for mileage, flashing LED readers can still be useful for diagnosing issues within these specific systems on these Volvo models.
Attempting to use a flashing LED tool on pin 7 for mileage reading is not only futile but can also lead to misdiagnosis or confusion. Personal experiences have shown that trying this approach based on initial, incorrect information can be misleading and ultimately unproductive.
To definitively prove the capability of reading 96-97 850 mileage using a flashing LED tool on OBDII pin 7, verifiable video evidence is necessary. Such evidence would need to clearly show the year and model of the vehicle, demonstrate the button presses and corresponding LED flashes, and include a synchronized time source to verify the frequency of the process. Furthermore, a controlled mileage test with pre and post readings would be required to confirm any mileage increment. Until such evidence is presented, the assertion that light LED OBDII readers can read mileage on ’96-’97 Volvo 850s via pin 7 remains unsubstantiated.
In conclusion, for accurate mileage readings on 1996-1997 Volvo 850 models, relying on a light LED OBDII reader connected to pin 7 will not yield results. The correct approach involves utilizing an ELM327 device configured with the KWPD3B0 protocol. Light LED tools serve different diagnostic purposes within these vehicles, focusing on systems accessed through pins 3, 6, and 13. Understanding these distinctions is key to effective Volvo 850 diagnostics and maintenance.
