Navigating the world of car diagnostics can be complex, especially when utilizing OBDII Bluetooth car diagnostic tools for vehicle modifications. This article delves into a firsthand account of using the Jscan app, a popular choice for Jeep owners, on a Jeep Patriot. The experience highlights potential pitfalls when altering vehicle settings such as tire size and Daytime Running Lights (DRLs) using such tools, and the subsequent issues encountered. This real-world scenario underscores the importance of understanding the capabilities and limitations of Mestart Obdii Obd2 Bluetooth Car Diagnostic interfaces and associated software when performing DIY vehicle adjustments.
The user initially employed the Jscan application to adjust tire size parameters and modify the DRL configuration on their Jeep Patriot, aiming to switch from high beam DRLs to low beam and sidelights. However, these seemingly straightforward modifications led to unexpected complications. The day following these adjustments, the vehicle’s engine light illuminated, and the Jeep Patriot entered limp mode, significantly restricting its performance.
Troubleshooting the issue proved to be a time-consuming process. The diagnostic trouble code identified was P0610 TRANS CONTROL, pointing towards a transmission control system malfunction that triggered the limp mode. To rectify the situation, the user undertook a series of steps, beginning with a hard reset of the vehicle’s electronic control unit (ECU). This involved disconnecting the battery and, crucially, draining any residual circuit charge by connecting the disconnected positive and negative battery cables together. This step is essential for a complete system reset and was maintained for approximately half an hour.
Following the battery reconnection, a relearning process for the vehicle’s systems was initiated. This involved cycling the ignition switch through the off and on positions multiple times, followed by allowing the engine to run and idle until it stabilized at around 800 RPM. This procedure allows the engine control systems to recalibrate and relearn necessary operating parameters.
After this reset and relearning sequence, the user re-engaged with the Jscan app to diagnose and rectify the initial setting changes. Navigating to the settings menu within the Jscan interface, they meticulously reviewed the adjustments made to tire size and DRL settings. The goal was to revert all parameters back to their original factory configurations. Subsequently, an advanced scan was performed using Jscan, and all stored diagnostic trouble codes were cleared.
Upon rescanning, the previously persistent P0610 code was no longer present. However, new codes emerged: B1634, B1630, and B1638, all related to HIGH BEAM CONTROL CIRCUIT FRONT CONTROL. Despite these new codes, a test drive revealed that the engine light had extinguished, and the vehicle was no longer in limp mode, indicating a partial resolution.
Contacting the Jscan manufacturer provided further insight. The manufacturer confirmed that the Jscan app may not be fully compatible with tire size adjustments on the Jeep Patriot model, acknowledging a potential limitation of the software in this specific application.
Currently, the vehicle exhibits persistent codes B1633, B1634, and B1638, all pertaining to high and low beam circuit issues. Functionally, the car operates normally as long as modifications to DRLs or tire size are avoided. The user notes a minor speedometer discrepancy due to the tire size difference and an anomaly where the high beams activate momentarily when switching to low beams, likely linked to the headlight control circuit codes.
Further experimentation with Jscan, including attempts to activate HIDs and other settings, consistently resulted in the reappearance of the engine light and limp mode, emphasizing the instability introduced by these modifications on this particular vehicle using this specific diagnostic tool. The user mentions utilizing aftermarket HID projector headlights connected through relays, suggesting that the vehicle’s computer system might be detecting the altered electrical load or configuration of the headlight system, contributing to the error codes.
Considering alternative diagnostic solutions, the user is contemplating exploring the Appcar Diagfca tool, questioning whether similar issues would arise when attempting tire size or DRL modifications with different software. This experience serves as a cautionary tale for users of mestart OBDII OBD2 bluetooth car diagnostic tools and similar applications. While these tools offer considerable convenience and customization options, compatibility issues and unintended consequences can occur, particularly when altering critical vehicle system parameters. Thorough research, understanding the limitations of the diagnostic tool, and proceeding with caution are paramount when undertaking DIY vehicle modifications using OBDII diagnostic interfaces.
