A 2010 Chevrolet Aveo owner is experiencing a no-crank, no-start condition unless the battery cables are touched together. Even when started, the “Hold” light flashes and the check engine light illuminates. The vehicle owner has checked all fuses, but a scan tool (Snap-on Solus and Actron generic scanner) cannot communicate with the vehicle. This article explores potential causes and solutions for this no-communication issue when using a Chevrolet Aveo Scan Tool.
Understanding the Problem: No Scan Tool Communication
The inability of a scan tool to connect with a Chevrolet Aveo’s onboard computer system prevents retrieval of diagnostic trouble codes (DTCs). Without DTCs, pinpointing the root cause becomes significantly more challenging. In this case, the Aveo exhibits a no-start condition coupled with warning lights, further complicating the diagnostic process. The fact that the vehicle starts after momentarily connecting the battery cables suggests a potential electrical issue.
Possible Causes of Communication Failure
Several factors can contribute to scan tool communication failures in a Chevrolet Aveo:
- Faulty PCM (Powertrain Control Module): A malfunctioning PCM can disrupt communication with scan tools. Given that the Solus scanner works on other vehicles, a faulty PCM is a strong possibility in this scenario.
- Wiring Issues: Damaged or corroded wiring within the CAN (Controller Area Network) bus system can interrupt communication between the OBD-II (On-Board Diagnostics) port and the PCM. Pins 6 and 14 on the OBD-II connector are crucial for communication and should be checked for damage and proper resistance.
- Low Battery Voltage: While all fuses are reported good, a weak battery or poor connection can prevent the PCM from powering up sufficiently for communication. The act of touching the battery cables together may temporarily boost voltage enough for a start.
- OBD-II Port Issues: Although less common, a damaged or faulty OBD-II port can hinder communication. Inspecting the port for bent or broken pins is essential.
- Incompatible Scan Tool: While unlikely given the use of a professional-grade Solus scanner, ensuring compatibility with the specific year and model of the Aveo is crucial.
Diagnosing the Problem
A systematic approach is crucial for diagnosing the communication issue:
- Verify Battery Voltage: Confirm a stable battery voltage above 12.6 volts with the engine off.
- Inspect OBD-II Connector: Examine the connector for physical damage and ensure a secure connection with the scan tool.
- Check Wiring and Connections: Visually inspect the wiring harness leading to the OBD-II port and PCM for damage, loose connections, or corrosion. Pay particular attention to pins 6 and 14. Measuring resistance between these pins and the PCM connector can help identify wiring faults.
- Test with a Known-Good Scan Tool: If possible, try another known-working scan tool on the Aveo to rule out scanner compatibility issues.
Conclusion
The no-communication issue with the Chevrolet Aveo scan tool, combined with the unusual starting procedure, points towards a significant electrical problem, potentially a faulty PCM or related wiring. While the customer opted not to pursue repairs, further diagnosis following the steps outlined above is necessary to definitively identify the root cause. Addressing the underlying issue is vital for resolving the no-start condition and ensuring the vehicle’s proper operation.
