DIC Message

JohnDar

Prolifically Gabby Member
While driving up to our site (w/o trailer) yesterday, I heard a ding and saw “ENGINE POWER IS REDUCED” on the DIC and the Check Engine light was on. Truck was holding cruise speed of 75, though. Got to a rest area and the idle was OK, all gages good, so I shut it off and used the facility. Truck started up OK, but as I was entering the freeway, it struggled to get to 55 and started to drop. Then it sped up and held 75 for the next 100 miles to the site. So, tomorrow morning it goes to the GMC dealer in Cheboygan to get checked out. Guess might be the MAF sensor, based on what I could read online.


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porthole

Retired
When you get the reduced engine power message on some of the vehicles it is not reduced until the next startup.
So if possible, don't shut the truck off until really necessary.
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
John, did you get a check engine light? Maybe go by an AutoZone and get them to use their OBD scanner on it, check to see if it registered any codes.

My dad bought a product called "FIXD" it's a bluetooth OBDII scanner that plugs into the port, then you read with an app on your smartphone. It gives "everyday language' explanations of what the problem is, and how serious it is, and how quickly it needs to be addressed and even offers help on where to get it fixed.

https://www.fixdapp.com/

I have used it on my car to diagnose a "check engine" light, and ran it on the truck as well when we had the "check engine" come on, but then go off later. There are many options out there, this was a 2-pack so that's the only reason he got this brand.
 

CoveredWagon

Well-known member
If I remember correctly you DO NOT have to use DEF fluid. If you do use DEF low fluid will do that to you. Also a full exhaust trap will do that.
 

JohnDar

Prolifically Gabby Member
If I remember correctly you DO NOT have to use DEF fluid. If you do use DEF low fluid will do that to you. Also a full exhaust trap will do that.

No DEF, my truck pre-dates that stuff. Fortunately, we also have the wife's SUV here with us. Just hope it doesn't have to limp the 19 miles to the dealership. Since I'd be almost to the dealer before reaching the nearest AutoZone, might just as well go all the way. I've been to this dealer before for service on the truck while up here and they've been very good. As it is, this truck has not been a maintenance queen the almost 10 years I've owned it.
 

JohnDar

Prolifically Gabby Member
John, did you get a check engine light? Maybe go by an AutoZone and get them to use their OBD scanner on it, check to see if it registered any codes.

My dad bought a product called "FIXD" it's a bluetooth OBDII scanner that plugs into the port, then you read with an app on your smartphone. It gives "everyday language' explanations of what the problem is, and how serious it is, and how quickly it needs to be addressed and even offers help on where to get it fixed.

https://www.fixdapp.com/

I have used it on my car to diagnose a "check engine" light, and ran it on the truck as well when we had the "check engine" come on, but then go off later. There are many options out there, this was a 2-pack so that's the only reason he got this brand.

Being a gadget freak, I might have to get a set of those...for next time.
 

Lynn1130

Well-known member
John, I like the Edge unit and you can get them with the ability to change tunes or just monitor. Mine just monitors but it has helped several times with information to relay to the dealer on issues. A couple of things. The MAF as you mentioned and also, when was the fuel filter changed last? Even with only a few miles on the filter, bad fuel can plug it in an instant and send you into limp. Just a thought or two.
 

JohnDar

Prolifically Gabby Member
John, I like the Edge unit and you can get them with the ability to change tunes or just monitor. Mine just monitors but it has helped several times with information to relay to the dealer on issues. A couple of things. The MAF as you mentioned and also, when was the fuel filter changed last? Even with only a few miles on the filter, bad fuel can plug it in an instant and send you into limp. Just a thought or two.

The fuel filter was changed several months ago, but I did put a few gallons in to top off at a national brand name station I don’t normally use before coming up here.
I didn’t actually go into limp mode, but it was close for a minute or two. That possibility crossed my mind, as well.


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Silverado23

Iowa Chapter Leaders
John, did you get a check engine light? Maybe go by an AutoZone and get them to use their OBD scanner on it, check to see if it registered any codes.

My dad bought a product called "FIXD" it's a bluetooth OBDII scanner that plugs into the port, then you read with an app on your smartphone. It gives "everyday language' explanations of what the problem is, and how serious it is, and how quickly it needs to be addressed and even offers help on where to get it fixed.

https://www.fixdapp.com/

I have used it on my car to diagnose a "check engine" light, and ran it on the truck as well when we had the "check engine" come on, but then go off later. There are many options out there, this was a 2-pack so that's the only reason he got this brand.

If you have an active on-star subscription you can talk with an Onstar agent. Ask them to run a diagnostic. They can tell you any codes and also intermittent codes that may have tripped. They can can then send that information to dealer service if needed too. very handy if you have intermittent codes flash briefly while driving.
 

JohnDar

Prolifically Gabby Member
If you have an active on-star subscription you can talk with an Onstar agent. Ask them to run a diagnostic. They can tell you any codes and also intermittent codes that may have tripped. They can can then send that information to dealer service if needed too. very handy if you have intermittent codes flash briefly while driving.

Thanks, I didn’t know that. I’ll give that a try before we head up to the dealer.


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JohnDar

Prolifically Gabby Member
If you have an active on-star subscription you can talk with an Onstar agent. Ask them to run a diagnostic. They can tell you any codes and also intermittent codes that may have tripped. They can can then send that information to dealer service if needed too. very handy if you have intermittent codes flash briefly while driving.

I contacted OnStar and they found a P0101 code. Something with the air induction system. It’s now at the shop. Thanks for the tip!

Got it back. Appears it was a dirty MAF sensor. They cleaned it and it seemed to be OK.

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Last edited:

Silverado23

Iowa Chapter Leaders
I contacted OnStar and they found a P0101 code. Something with the air induction system. It’s now at the shop. Thanks for the tip!

Got it back. Appears it was a dirty MAF sensor. They cleaned it and it seemed to be OK.

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Your welcome. I am happy to hear that On-star worked for you. So easy and a great feature that is not well advertised.
Falls under "Advanced Diagnostics" https://www.onstar.com/us/en/support/advanced-diagnostics/
 

rnewk52

Active Member
What a coincidence. We were pulling our camper home from the mountains last Sunday and got the same message and check engine light on, and reduced power. Luckily our friend was behind us and towed the camper home. Went to dealer Monday, exact same code and diagnosis. He also replaced the air filter? Towed camper to the lake today and all is good.
 

mlpeloquin

Well-known member
Had a heck of a time with the DIC reporting cor sensor bank problems. Will reduce engine speed to 55mph etc.. Just kept clearing the codes. Finally brought the truck into the GMC dealer and $486.00 later nothing is wrong. Even with the codes present. So I just kept clearing the codes. The codes were about the font and rear co2 sensor banks being faulty. Finally a new code. The DEF heaters were open! Brought it in and they were replaced for free under warranty. Been fine ever since. Wish I could get my $486.00 back. Nothing wrong with the co2 sensors. Systems are so complex that the computer systems cannot really find the source of the problems. Heaters must have been intermittent. You would think that an engineering note would be issued to look at the DEF heaters with continuous reports of co2 sensor banks being a problem and testing good.
 

CoveredWagon

Well-known member
Had a heck of a time with the DIC reporting cor sensor bank problems. Will reduce engine speed to 55mph etc.. Just kept clearing the codes. Finally brought the truck into the GMC dealer and $486.00 later nothing is wrong. Even with the codes present. So I just kept clearing the codes. The codes were about the font and rear co2 sensor banks being faulty. Finally a new code. The DEF heaters were open! Brought it in and they were replaced for free under warranty. Been fine ever since. Wish I could get my $486.00 back. Nothing wrong with the co2 sensors. Systems are so complex that the computer systems cannot really find the source of the problems. Heaters must have been intermittent. You would think that an engineering note would be issued to look at the DEF heaters with continuous reports of co2 sensor banks being a problem and testing good.

So what did the dealer claim they did for $486 ? I had an similar issue with my 04 Buick. I complained and protesters to the dealership manager and received a heck of a reduction in the bill.
 

porthole

Retired
Had a heck of a time with the DIC reporting cor sensor bank problems. Will reduce engine speed to 55mph etc.. Just kept clearing the codes. Finally brought the truck into the GMC dealer and $486.00 later nothing is wrong. Even with the codes present. So I just kept clearing the codes. The codes were about the font and rear co2 sensor banks being faulty. Finally a new code. The DEF heaters were open! Brought it in and they were replaced for free under warranty. Been fine ever since. Wish I could get my $486.00 back. Nothing wrong with the co2 sensors. Systems are so complex that the computer systems cannot really find the source of the problems. Heaters must have been intermittent. You would think that an engineering note would be issued to look at the DEF heaters with continuous reports of co2 sensor banks being a problem and testing good.


Your dealer failed you there.

With codes present there is a problem. All the diagnostic procedures have an outcome, and if codes are consistent there is a repair.

i have been on both sides of this, as a consume and as a new car tech fo rover 20 years.
You need to step up your complaint with GM, there is no reason why you should not get your money back. Although your complaint is mainly with the dealer (if they charged you, they didn't charge GM) the fact remains, work was eventually done, was covered under warranty and you paid for something you didn't get.

You should pay because you dealer did not know how to fix the problem.

And keep in mind, all emission component repairs warranties are dictated by the Federal G. They do not fall under basic new vehicle warranties.
 

Gaffer

Well-known member
John, did you get a check engine light? Maybe go by an AutoZone and get them to use their OBD scanner on it, check to see if it registered any codes.

My dad bought a product called "FIXD" it's a bluetooth OBDII scanner that plugs into the port, then you read with an app on your smartphone. It gives "everyday language' explanations of what the problem is, and how serious it is, and how quickly it needs to be addressed and even offers help on where to get it fixed.

https://www.fixdapp.com/

I have used it on my car to diagnose a "check engine" light, and ran it on the truck as well when we had the "check engine" come on, but then go off later. There are many options out there, this was a 2-pack so that's the only reason he got this brand.

The link took me to the product but it said for all gasoline powered vehicles. The following is from a review:

Fixd will work on:

  • Vehicles manufactured after 1996
  • Vehicles that run on gas or are hybrids
If you have an earlier vehicle or a vehicle that is diesel, this is not a product for you. You see, the OBD-II standard was implemented for all vehicles in the U.S. that were introduced to the market after 1996.

This is for another review:
Fixd will also work with hybrids, and the company is currently beta testing diesel-based vehicles, and says that it's "had success with models made after 2008."

So it may be a little early to get one for your diesel truck. Guess I will get an Edge for my new truck. Loved the last one but I sold it with my old truck.
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
Hmmm! Interesting. We used it on a diesel. But since I didn't actually buy it, I can't say which actual product my dad bought. He intended it for use on gas vehicles. But I did use it on the truck.


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JohnDar

Prolifically Gabby Member
Although I can use the Advanced Diagnostics with OnStar, I ordered the BlueDriver OBD-II reader. Just got it late this afternoon, so I’ll check it out tomorrow.
My (much) early birthday present arrived yesterday. A Cobra F-Max offset driver with the senior flex shaft.

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