Jump to content

Recommended Posts

Posted

2016 GMC Sierra fan blowing, temp gauge at 160 and I have Engine warning light on for P0156, P0157 (O2 sensor codes nothing to do with engine temp). Clear the ODB codes,  temp gauge corrects and blower stops. One reason has to be electrical. I am not a mechanic by a long shot! Just changed the sensors and still throwing the codes. Bummin'!

Posted

Let me correct my last post.  This temporarily made the issue go away but I ultimately think it cleared the computer memory.  Issue came back again.  The issue is the thermostat.   It’s a simple replacement and takes about 20 minutes.   I replaced and all issues went away and I also noticed my heat in the cabin got significantly hotter which is also a sign of a bad thermostat.  I would replace both the thermostat and sensor since they’re in the same spot.   

  • 11 months later...
Posted

Replaced battery recently. Replaced sensor and thermostat but fans still coming on high and no fluid moving through hoses. Could it be a bad new thermostat? Should we have scanner hooked up to see what codes come up?

Posted
2 hours ago, Dena said:

Replaced battery recently. Replaced sensor and thermostat but fans still coming on high and no fluid moving through hoses. Could it be a bad new thermostat? Should we have scanner hooked up to see what codes come up?

Did you replace with OEM or aftermarket sensor and thermostat? I had bad experience several months after replacing my thermostat with aftermarket. A Motorad to be specific. Replaced it again with an OEM but went with a lower temp (194⁰) one and it's been fine every since.

  • Like 1
  • 4 months later...
Posted

My 2016 GMC Sierra with the 5.3L has done the fan on high for 3 straight years. I live in Michigan and the only time the fan turns onto high is in the Spring and Fall time periods when we temperatures between 40F & 60F degrees. So any time its in the 40's or 50's it seems to happen, then in the winter when its teens, 20's and 30's it never turns on. The same goes for the summer when its 70's, 80's, 90's it never turns on. I have replaced my coolant sensor with an AC Delco OEM unit. I disconnected the battery for 10 minutes and the problem temporarily went away, but came back two days later. Next I've purchased a thermostat, I plan to change it out this week. I am slowly doing one thing at a time to see what the root cause was for my situation to hopefully help the next person. I have no codes being thrown, there is no check engine light coming on.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    250.5k
    Total Topics
    2.7m
    Total Posts
  • Member Statistics

    342,915
    Total Members
    8,960
    Most Online
    ChristopherDobson
    Newest Member
    ChristopherDobson
    Joined
  • Who's Online   5 Members, 0 Anonymous, 1,296 Guests (See full list)

  • Latest Articles

  • Posts

    • Monthly payment is only part of the equation. With today's prices and interest rates, I'd look at the total monthly cost: payment, insurance, registration, fuel, maintenance, and expected repairs. A vehicle that fits comfortably into your budget is usually the better choice than stretching for a higher trim. I've also kept my vehicles longer over the past few years. New cars have gotten expensive enough that driving one for 10+ years, while staying on top of maintenance, often ends up being the most cost-effective approach.
    • 10 Ford and Chevy engines proven to reach 300,000 miles   You may note a common 3K OCI on this list of gas motors. I skipped over the diesels. Dh'O. 
    • Thanks newdude!  By the time manual selection is needed, I'm probably too much of a control-freak to depend on the transmission sensing braking to activate automatic downshifting.  I would be anticipating the situation and already be manually downshifting.   This truck replaced a 2004.5 LLY diesel with the Allison 5-speed.  Putting it in T/H made noticeable differences (when the torque converter locked, upshift points, downshift behavior).  On this 2024 gasser with the 10L1000 I haven't been able to detect much, if any, difference.  Ok, I can never tell now when the torque converter locks up.  But I also don't notice differences in shifting.  For downhills, I've probably already manually downshifted by then anyway.  Since it's also more awkward (than the 2004.5) to engage/disengage I don't even bother.  Or maybe it doesn't really matter with just a 3k lb. camper in the bed?   Thanks also for the list of reasons the charging system might select various voltages.  However, what I am seeing doesn't fall into any of those categories.  It very definitely, and very consistently, rises after coasting/braking.  Maybe not immediately, but not very long after coasting/braking.  Very consistently drops voltage when no longer coasting/braking.  It might also be interacting with the camper battery charging (I might disconnect the camper and see if it changes the charging behavior).  I also need to recheck turning on headlights for when I want to force it to charge the camper.   Another JR, in June I converted the camper to LiFePO4.  Since it's not a good idea to try to charge lithiums directly using truck, I installed a Victron Orion XS DC-DC charger (which BTW is AMAZING!!).  Being cheap, I only had to buy that one item (besides the battery, of course) to do the conversion.  The camper OEM 120v battery charger (only 19 years old and works perfectly) and the truck feed the input to the DC-DC charger (not at the same time).  But I didn't want the camper charger feeding back to the truck so I kept the old separator.  I considered replacing the separator with a 30amp diode but that means more work and might add another 1/2 volt drop.  One thing that surprised me was the voltage drop over the long 10awg wire run, so I can only charge smoothly at 8 amps (because the DC-DC charger is completely configurable).  Another reason I don't want an added voltage drop with the diode.  I might also be a little lazy but all this work is being done under the sink with a small cabinet opening.    
    • apparently CA smog is (or at least was)  checking that the vehicle is using the oem and/or a ca smog approved tune, so I expect you'll fail inspection doing it.
    • yes, leaking exhaust will mess up o2 sensor readings, which in turn messes up fuel trims.
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...