Jump to content

2012 GMC Sierra cooling fan issue

jaded13640

Recommended Posts

jaded13640 Enthusiast

jaded13640

Posted
Posted

Hi guys, I've got a customer with a 2012 Sierra 1500 4x4 with the 5.3 that's having a cooling fan issue.

 

He says that the primary fan is not running and so the secondary fan runs all the time.

 

He says he's changed the relay. I assume he's referring to the relay in the fuse block.

 

I recall an Intrepid I had once that had a fan control unit down at the fans. It failed and both fans ran continously.

 

What could cause the this issue?

 

If the primary fan fails does the secondary fan run all the time or should it be cycling on and off as well?

I'm not familliar enough with this vehicle to give him a quote. Until I at least understand how that system works I don't know what to tell him.

 

I'm burried in work at the moment and would prefer to not have yet another vehicle sitting here until I at least know where to start looking for the issue.

 

I've searched my labor guides for clues and have come up empty.

 

Any help would be greatly appreciated.

 

Thanks,

 

Wayne

00Silverado4x4 Senior Enthusiast

00Silverado4x4

Posted
Posted

Fuses good? Proper relay replaced? Was the relay he replaced the correct part? Power going to fan? Does fan have a good ground? Is there any problem in the wiring, loose, melted, disconnected?

 

Unfortunately you need to take a look at it prior to being able to even start troubleshooting such a problem.

jaded13640 Enthusiast

jaded13640

Posted
  • Author
Posted

What I'm asking is this, Is there a controler for the fans other than the relay in the fuse block? Is this a common issue with these vehicles?

 

You know how this goes, someone calls, tells you what it's doing and asks you how much to fix it. I didn't give him a price or anything, I wanted to do a little research first.

 

I've got limited parking here at my shop and at the moment, EVERY spot is full. I just want to get an idea of what I'm looking at before I have him drop the truck off.

 

06sieraz71, like I said, I don't have it here yet. I'm just trying to get an idea as to what might be going on, what common issues are with this vehicle and that sort of thing before I have him bring it out. And to give him an idea of what we're looking at cost wise. I know that sometimes can't happen. I know sometimes you have to do a search and destroy mission to figure out what's going on. But sometimes it's a common issue and the forums are useful.

 

govtech4, as I understand it there are no trouble codes. And again, it's not here yet for me to scan. I'm looking for tips and ideas in advance of getting here and checking it out to maybe help speed up the process of elimination.

 

8.1hd/allison, Yes, I will scan it but he tells me there's no check engine light. And yes, a diagram would be extremely useful. Do you have one or a link to one? That would be very helpful.

 

Thanks to all that replied, Again, I haven't got the truck here yet, I'm doing research in advance of it coming here and to try to give the guy a rough idea of what this is going to cost him to fix it. Unfortunately people have gotten accustomed to being able to call around to shops to "shop around" for the best price. This probably isn't one of those deals. This is probably going to be a hands on diagnosis and not a "oh, yea, it's the canootin valve and will cost you 200 bux" kind of thing.

 

Thanks again,

 

Wayne

Badbird2000 Enthusiast

Badbird2000

Posted
Posted

This may be way off, but I remember in my 2000 T/A, I was sitting in traffic one day and it started heating up quick, like near 240.. I was near the dealer so I pulled in. A plastic fan had wrapped around one of the fans, so it couldn't spin at all. Keep in mind, this was in Florida in the summer. I would hope the owner would look at something that obvious right up front..

newdude Senior Enthusiast

newdude

Posted
Posted

Some food for though...

 

Cooling Fan Control w/o HP2

System Overview

The engine cooling fan system consists of 2 electric cooling fans and 3 fan relays. The cooling fan relays are arranged in a series/parallel (S/P) configuration. This allows the engine control module (ECM) to operate both fans together at low or high speeds using 2 fan control circuits. The cooling fans receive positive voltage from the cooling fan relays, which receive battery positive voltage from the underhood fuse block. The cooling fans are supplied a ground at G100 and G101.

 

Low Speed Operation

The ECM applies ground to the coil side of the cooling fan low speed relay. This energizes the coil and applies voltage directly to the left cooling fan through the switch side of the low speed relay. The left cooling fan is connected in series to the right cooling fan through the de-energized series/parallel (S/P) cooling fan speed control relay. The result is a series circuit that operates both fans at low speed.

 

High Speed Operation

The ECM applies a ground to the coil side of the cooling fan low speed relay, the S/P cooling fan speed control relay, and the cooling fan high speed relay. When energized, the high speed fan relay applies voltage directly to the right cooling fan through the switch side of the relay. Simultaneously, the low speed fan relay and the S/P speed control relay provide ignition voltage and a direct path to ground for the left cooling fan. During high speed fan operation, both engine cooling fans have their own ground path. The result is a parallel circuit with both fans operating at high speed.

 

Two codes can set, P0480 and P0481. Relay or motor are most likely culprits unless there is a wiring issue. The motors can be somewhat common.

jaded13640 Enthusiast

jaded13640

Posted
  • Author
Posted

Some food for though...

 

 

Two codes can set, P0480 and P0481. Relay or motor are most likely culprits unless there is a wiring issue. The motors can be somewhat common.

 

 

Newdude, excelent stuff. Thanks for taking the time to post it.

 

Wayne

  • 10 months later...
2010CREWCAB New Member

2010CREWCAB

Posted
Posted

I am Having a Simular issue, Currently the Primary Fan is blowing the Fuse, In the begining it wasnt working so the secondary fan was running non stop, which was extra loud. so the other day i found the Fuse and replaced it, fan came on for about 10 minutes then fuse popped. Today I checked all the wiring and everything looks good, Im at at standstill on what to do!!

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,840
    Total Members
    8,960
    Most Online
    appletrav
    Newest Member
    appletrav
    Joined

  • Who's Online   3 Members, 0 Anonymous, 399 Guests (See full list)

  • Latest Articles

  • Posts

    • newdude
      2 speed transfer case optional now?

      By newdude · Posted

      This is a 1/2 ton thing ONLY.  All HDs 2020-2026 have the two speed transfer case, with Autotrac as an option.     1/2 tons 2019-2026, regular 4x4s come with a single speed case (no 4LO!), and trucks with Z71 ordered, or all Trail Boss trucks come with the 2 speed case.  2 speed case is also an option on WT, and is also standard on High Country.  
    • newdude
      Different requirements for oil filters?

      By newdude · Posted

      2013 5.3 still to this day calls for the PF48 filter.  Which as a 15psi bypass pressure.     There is a TSB, 17-NA-157 that talks about the PF-63 and PF-64 filters which have a higher bypass rating of 22psi.    TSB HERE - temp.xml   "Beginning in 2012, the oil pumps began to regulate main gallery feedback instead of pump out pressure. This means that the oil pump now does not begin to regulate until pressure is built up to the main gallery. This change reduces the amount of time it takes to provide oil to the engine bearing and lifters during extreme cold start conditions.  Main gallery feedback oil pump control systems are present on the following engine families which use Spin-on oil filters: Small Gas Engine (SGE), Large Gas Engine (LGE), High Feature (HFV6) Gen2 and Small Block Gen5 gasoline engines. These engines with the main gallery feedback oil pump control systems are factory built with an ACDelco® oil filters"   It also calls out what engines use those filters.  The gen 4 small blocks were not on that list (LMG, LC9, L9H, L92, L94, L20, L96).  Gen 5 small blocks use the higher pressure filter.          That all said...   Your 7045 Napa filter is the PF63 equivalent, with 22psi bypass.  You are already using the higher bypass pressure filter.  You CAN keep using it, you don't technically have to use it though.  
    • Grumpy Bear
      Different requirements for oil filters?

      By Grumpy Bear · Posted

      Do you know WHY the filter relief setting was increased to 22 psig?    When the new system goes into the second stage the pump volume ramps up considerably. It was found that the 15 psi filter bypass setting put the filter in bypass on a warm engine when the second stage was activated. Raising the filter bypass setting forced the filter to do what it designed to do. Filter. Preventing debris from circulating during high load, high rpm operation.    So next question is how did GM find this out? VLOM/lifter failures and a deep dive by Melling Corp.    Last question. Is it required? Look at it like this; a motor may be equipped with a rev limiter. But it only works if the set point in reached. That 22 psig setting only matters if the pressure differential across the filter media exceeds 15 psig during normal warm operation. Second stage kicks in around 3000-3500 rpm.    I can't answer your question because I don't know you and how you use the truck. But I think there is enough information here to let you decide for yourself. 😉
    • Coastie05
      give me some tips to make my truck look better

      By Coastie05 · Posted

      Go back to OEM wheels. 
    • newdude
      2020 Trailboss 6.2 replacement

      By newdude · Posted

      Probably not their first rodeo, so it should go as planned most likely.  Typically the service manager or tech doing the swap will put some seat time to shake it down after they get it all put back together.  We usually put 50-100mi before we hand them back so if something happens, its not after you get it.  A coolant leaks, oil leaks, a ground left off or loose, vibration, etc.     The new engines so far have been good?  There's been a couple that have popped out there again (the replacement engine) but most have been okay.  

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...