Experiencing a no-start issue with your car can be incredibly frustrating, especially when you’re on a tight schedule. For owners of older vehicles, like a ’94 Ford Mustang 3.8L V6, diagnosing these problems might seem daunting. One Mustang owner recently encountered a perplexing situation: their car wouldn’t start, accompanied by an unusual radiator fan activation and OBD2 scanner communication failure. Let’s delve into the symptoms and explore potential troubleshooting steps, especially when using a tool like the Actron CP9575 OBD2 scanner.
The owner reported that after years of driving with a persistent catalytic converter code, their Mustang suddenly refused to start. The battery, alternator, and starter were all checked and deemed functional – the engine was turning over, but not igniting. Adding to the confusion, the radiator fan would switch on as soon as the ignition was turned to the ‘ON’ position, even when the engine was cold. This fan behavior was intermittent at first, sometimes allowing the car to start after a few minutes, but later became constant, preventing the engine from starting altogether. Further complicating matters, the car’s A/C system malfunctioned, only blowing air through the defrost vents regardless of the selected mode.
To get to the bottom of the issue, the owner attempted to use two OBD2 scanners: the Actron CP9575 OBD II AutoScanner and the Actron CP9035F. Both scanners failed to communicate with the car’s computer system. This lack of communication is a significant clue, as it can point towards problems with the car’s Engine Control Module (ECM) or the communication pathways themselves. A faulty ECM might indeed prevent OBD2 scanners from connecting, hindering the diagnostic process.
The owner correctly checked the OBD2 connector under the dash, noting the presence of metal contacts in the expected pins, suggesting the connector itself was likely not the issue. The Vehicle Emission Control Information sticker confirmed the car was OBD II certified, which should ensure compatibility with OBD2 scanners like the Actron CP9575. The ECM part numbers provided, F4SB-14A624-HA and F4SB-14A459-A, raise a question about potential ECM mismatch, as the “F4SB” prefix is often associated with Ford Thunderbird or Mercury Cougar models rather than Mustangs of that era. While the ECM had been in the car for two years without prior issues, a mismatch or subsequent failure could be contributing to the current problems.
When facing such a no-start scenario with OBD2 communication failure and unusual electrical behavior like the radiator fan issue, several potential areas need investigation. A systematic approach is crucial. While the alternator itself was initially deemed “fine”, it’s important to consider the broader electrical system. Issues like a faulty ignition switch, wiring harness problems, or a malfunctioning sensor could all contribute to these symptoms. The Actron CP9575, while unable to initially connect for code reading, can still be valuable for diagnosing electrical issues. It can be used to check for voltage at various points in the system, test circuits for continuity, and potentially identify shorts or open circuits that might be affecting the ECM and other components.
In conclusion, the ’94 Mustang’s no-start condition, coupled with the radiator fan and OBD2 scanner communication problems, strongly suggests an underlying electrical or ECM-related issue. While the Actron CP9575 OBD2 scanner couldn’t initially pull codes due to the communication failure, it remains a useful tool for further electrical system diagnosis. The next steps should involve a thorough check of the car’s wiring, ignition system, and ECM, potentially utilizing the Actron CP9575 to perform targeted electrical tests. Consulting a professional mechanic familiar with older Ford vehicles might be necessary to pinpoint the exact cause and implement the correct repair.
