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eddo
Advanced Member
USA
311 Posts |
 Posted - 06/04/2015 : 10:43:47 AM
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Hey folks,
I'm working on a 2010 Chevy Express 3500 with the 6.6L Duramax (174,000 miles,) and it keeps throwing the DTC "P0483 Fan Rationality Check."
I am new to the world of Duramax's, and frankly have never seen this code in anything else. I can clear the code, drive the ever-lovin-snot out of the truck, and cannot get it to throw a code on me. But as soon as someone else drives it- the code shows, and Check Engine Light comes on.
Any ideas? Google search shows little help. I was told that this could be caused by the water temp not cooling down fast enough when the fan kicks on. Does that sound right to anyone? Based on this, I pulled the grill and blew the bugs out of the condensor, air cooler, and radiator- but the code came back the next day.
BTW- the truck is operating in Tucson, AZ where the temp has been 100 degrees plus all week, with very little humidity. Our first day over 100 degrees is when this started.
BTW2- Is it Duramax's? Duramaxes? Duramaxi?? lol
Thank for reading! |
Edited by - eddo on 06/04/2015 11:07:10 AM
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eddo
Advanced Member
USA
311 Posts |
Posted - 06/04/2015 : 2:31:35 PM
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and starting today, after a 100 mile run, I am now getting DTC P0402 (EGR Excessive Flow,) as well as O0483.
Could they be related at all? |
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Troy87
Senior Member
United States
52 Posts |
Posted - 06/10/2015 : 04:56:18 AM
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Sounds like, at lower/regular speeds the fan is not pulling enough air in to cool the engine. I would check the fan clutch, the fan relay, and grounds for the circuit.
P0483 Description
The electric cooling fan is controlled by the Engine Control Module (ECM) through the cooling fan relay based on inputs from the following components:
- The engine coolant temperature (ECT) sensor
- The intake air temperature (IAT) sensor
- The A/C selector switch
- The A/C refrigerant pressure sensor
- The vehicle speed sensor (VSS)
The ECM controls the cooling fan by grounding the cooling fan control circuit which turns ON the cooling fan relay. The cooling fan relay will be commanded ON when the following conditions are met:
- The engine coolant temperature reaches 106°C (223°F) or more.
- The A/C clutch requested.
- The vehicle speed is less than 38 MPH.
The cooling fan relay will be commanded ON regardless of vehicle speed when the following conditions are met:
- The engine coolant temperature is 151°C (304°F) or more.
- The A/C refrigerant pressure is high.
The cooling fan may be commanded ON when the engine is not running under a fan run-on conditions described in the electric cooling fan general description portion of the service manual.
Read more: http://engine-codes.com/p0483.html#ixzz3cewfX6iN |
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eddo
Advanced Member
USA
311 Posts |
Posted - 06/10/2015 : 07:32:42 AM
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Thanks Troy87! I ended up eventually finding some of this information, and it led me to replace the fan clutch. So far, so good! I can hear this fan clutch engage, where I could not hear the old one.
Thanks again! |
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2010 Chevy Duramax- P0483 Fan Rationality Check.
