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Getting a P0641 and P0449 code. Causing reduced power mode…

Customer Question
Getting a P0641 and...

Getting a P0641 and P0449 code. Causing reduced power mode ad stabiltrak off. I had a crank and cam shaft sensor codes so I re[laced them. Those codes went away. The others did not.

Mechanic's Assistant: Does the vehicle stall at low speeds? Does it sputter?

Forgot to mention it is a 2007 chevy tahoe ltz. Yes, It was sputtering and it stalled when I pulled in garage. It also would keep cranking when I tried to restart.

Mechanic's Assistant: Are you fixing your Tahoe yourself? What have you tried so far?

Yes I am fixing myself. Changed the cam shaft sensor, crank shaft sensor and belts. A few weeks ago the throttle body sensor code came on so I replaced that.

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

Truck has 170,000 miles.

Submitted: 11 months ago.Category: Chevy
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Answered in 29 minutes by:
9/25/2017
Chevy Mechanic: Dan, Technician replied 11 months ago
Dan
Dan, Technician
Category: Chevy
Satisfied Customers: 26,063
Experience: Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
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Customer reply replied 11 months ago
Hi dan
Customer reply replied 11 months ago
Not able to do that. I am hearing impaired.
Chevy Mechanic: Dan, Technician replied 11 months ago

These codes are unrelated, P0449 means a problem with the vent solenoid control circuit, most likely meaning the vent solenoid has failed but this would not cause the reduced power and stalling. P0641 means the 5v reference wire 1 is shorting out which would either mean wire is shorting or one of the components wire connects to is internally shorting. The common causes for that code is a failing oil pressure switch, failing fuel tank pressure sensor, or wiring. You can disconnect each component that is on thsi circuit one at a time to see if code stops setting if so replace component that stops code from setting when unplugged. If that doesn't change anything next step is to start checking wiring. Check for the harness near the transfer case to rub on the front propeller shaft. The 5-volt reference 1 bus provides 5 volts to the following sensors: Let me know if you have questions, thanks.

The manifold absolute pressure (MAP) sensor
The fuel tank pressure (FTP) sensor
The air conditioning (A/C) refrigerant pressure sensor
The accelerator pedal position (APP) sensor 2
The engine oil pressure (EOP) sensor
The camshaft position (CMP) sensor

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Customer reply replied 11 months ago
Unplugging temporarily one at a time won't damage anything, will it? Also, could it also possibly be the computer?
Chevy Mechanic: Dan, Technician replied 11 months ago

It could be the computer but it is about the least likely out of possible causes. Unplugging components will not cause damage. Let me know if you have questions, thanks.

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Customer reply replied 11 months ago
Thank you. I will let you know.
Chevy Mechanic: Dan, Technician replied 11 months ago

No problem, I'm happy to help. Let me know how it turns out or if you need anything, you can reply to this answer at any time without additional fees. I'd expect around a $400 repair if done at a shop depending on how long it took them to figure out problem. Thanks again and have a good evening.

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Chevy Mechanic: Dan, Technician replied 10 months ago

Ever get it figured out? Please do not forget to rate answer. Thanks.

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