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QUESTION: The 6.6L Duramax LLY engine in my ’04 GM pickup has 105,000 miles on it and a Check Engine light is showing. After scanning the ECM, I found out the problem is associated with diagnostic trouble code P0045 (boost-related issue concerning the turbocharger’s vanes). I delete it, and it comes back after a few hundred miles. My repair shop says the problem is more an inconvenience and not worth the expense of installing a new turbocharger. I am planning a boating trip up to Alaska and don’t want any major problems. Would this cause a breakdown or something close? Advice on how to handle this is appreciated.
ANSWER: Whenever a diagnostic trouble code is triggered, trying to determine its cause and making the appropriate repair is always the best way to proceed. Ignoring DTCs for too long is not recommended. The code in your truck’s ECM, DTC P0045, could pertain to the turbo’s vanecontrol solenoid, which receives a command from the ECM to change the angle of the vanes according to the load placed on the engine. The control solenoid has two circuits—High and Low. The ECM communicates with the solenoid to control the position of the turbo vanes. Changing the vane angles increases and decreases boost. If the ECM sends a signal to the solenoid and the solenoid doesn’t respond correctly within 1 second, the ECM senses there is a boost issue and triggers DTC P0045 and/or P003A. The causes for the code are numerous: a bad wire to the control solenoid, a bad or sticking control solenoid, or sticking turbocharger vanes. It could also be activated because boost pressure is bleeding from a leak in the intercooler boots or tubes. Usually, the cause is directly related to carbon/soot buildup either on the end of the boost-control solenoid or around the vanes inside the turbo. To get to the root of the problem, the first task is to use a scan tool and run a diagnostic on the solenoid by turning it on and off. According to GM’s 6.6L Duramax service manual, the vane-position sensor’s parameters should be 95 to 97 percent when it’s on, decreasing to almost 0 percent when it’s off. A sticking solenoid can be removed, cleaned, and reinstalled, while a defective part is easily replaced. If the solenoid checks out, then pressurize the boost tubes to the intercooler to see if there are any leaks from bad boots or loose clamps. If that part of the system is good, then the problem is likely associated with sticking turbo vanes, and that usually requires replacing the ’charger, because it’s very difficult to thoroughly clean the vanes. Any residue left behind will act like a magnet, quickly attracting soot, so the same problem would return months later. A good diesel shop can perform all the tests to diagnose and remedy the problem.
Diagnostic trouble code P0045 and/or P003A can be caused by numerous issues related to turbocharger vanes, including a bad wire to the control solenoid or a sticking solenoid or turbo vanes. It could also be triggered because boost pressure is bleeding...