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Subaru Intermittent P0028: Can We Duplicate It? NOT with the Flowchart!

This Subaru Forester came in with an intermittent P0028, but this video turns into a much bigger lesson than just finding the fault. The real value here is the troubleshooting process: how to test an output when you do not have bidirectional controls, how to identify a power-side switched solenoid circuit, how to manually energize the actuator safely, and how to confirm switch input operation without blindly following the OEM flowchart. In this case, the flowchart was absolutely ridiculous and you would have never found this fault by using it. Understanding circuit operation made the diagnosis faster and more accurate. Timestamps 00:00 Intro, symptoms, and intermittent P0028 overview 01:35 Bank identification and confirming the fault is on the left side 02:57 No bidirectional controls available, so testing old-school 03:40 Comparing left/right solenoid duty cycle and current flow 05:29 Solenoid and pressure switch location and system operation 05:58 Unplugging the opposite side to verify scan data 07:12 Wiggle testing and checking for harness/current drop issues 07:51 Scope testing the circuit and identifying a power-side switched output 09:47 Manually energizing the solenoid and watching switch response 12:00 Why applying battery voltage here will not damage the driver 16:29 Why both solenoid wires go to the ECM: current monitoring discussion 19:23 Clearing induced codes and confirming the fault is intermittent 21:19 What to do when the fault is gone: clear it and drive it 22:02 Teaching segment: output testing and switch input fundamentals 25:00 Why circuit identification gets muddy when both wires go to the ECM 33:02 Confirming pressure switch operation and bypass testing the input 40:20 Why the OEM flowchart is inefficient and misses the real test 47:47 Manually energizing the circuit again and catching the fault live 49:42 Proving the pressure switch is stuck open with the engine off 53:16 Final diagnosis: sticking variable valve lift diagnosis pressure switch 🔧 Looking for Deeper Training? Whether you're a DIYer, an aspiring tech, or a professional looking to sharpen your skills, join ScannerDanner Premium for next-level diagnostics training: 👉 Join Here – 14 Days for $1 https://www.scannerdanner.com/join-scannerdanner-premium.html On ScannerDanner Premium, you'll get: *In-depth classroom lectures straight from my book *Exclusive case studies with live vehicles pulled into class *Real-time troubleshooting using proven methods *Post help requests on our forum *Fundamental training on diagnosing automotive electrical and electronics systems. 📘 Want to Learn More About Diagnostics? Check out my field manual, Engine Performance Diagnostics, available as both an eBook and paperback at: 👉 https://linktr.ee/scannerdanner ScannerDanner Tools: https://linktr.ee/scannerdanner ⚠️ Disclaimer: ScannerDanner LLC is not responsible for misuse, unauthorized changes, or incorrect application of any information provided. Always follow proper safety protocols when using tools, equipment, or procedures discussed in this video. Use this content at your own risk.