Well, I bought a new truck and sold my 2016 lml. I bought a 2013 gmc sierra 3500 with the lml in it. It had a lot less miles and my other truck was giving me fits with injectors. When I bought it, it had no codes. The next morning, I had 2 glowplug circuit open codes for cylinders 8 and 3. I thought, no big deal, I will just put in a couple of glowplugs. The day after that, 2 more codes popped up. Cylinders 8 and 3 again. This time it said cylinder contribution/balance. I thought it might be related to the glow plugs, so I cleared them and drove the truck until it got warmed up. Then I had them come back, but not the glow plugs. I know that 8 and 3 are in the same injector group...so, now I am thinking it is one or both injectors. The truck runs fine, but a little doggy compared to my 2016 model. No smoke or misfires though. Also, another issue I discovered shortly after buying it is that the engine brake doesn't work at all...not in the slightest bit. It comes on and says it's on, but it does nothing. Anyways, do you guys think injectors, wiring, or glowplugs? Or something else entirely?
Got a couple of cylinder contribution codes
- Thread starter flyinwrenches
- Start date
Is the truck stock?
First thing I would do is check the Injector balance rates. Also wouldn't hurt to check compression and rule out an issue with those cylinders.
Here is the description for those balance codes.
Circuit/System Description
The engine control module (ECM) monitors changes in crankshaft speed using input from the crankshaft position sensor. The ECM adjusts the fuel delivery to each cylinder in order to minimize crankshaft speed changes. If the ECM identifies a cylinder or cylinders requiring an excessive adjustment of fuel in order to maintain the correct crankshaft speed, a DTC will set.
Conditions for Running the DTC
The fuel injector balance correction is greater than the calibrated limit.
First thing I would do is check the Injector balance rates. Also wouldn't hurt to check compression and rule out an issue with those cylinders.
Here is the description for those balance codes.
Circuit/System Description
The engine control module (ECM) monitors changes in crankshaft speed using input from the crankshaft position sensor. The ECM adjusts the fuel delivery to each cylinder in order to minimize crankshaft speed changes. If the ECM identifies a cylinder or cylinders requiring an excessive adjustment of fuel in order to maintain the correct crankshaft speed, a DTC will set.
Conditions for Running the DTC
- DTCs P0117, P0118, P0335, P0336, P2146, P2149, P2152, P2155 and P062C are not set
- The ECT is more than 40°C (104°F).
- Engine is running.
- The engine RPM is between 600-2,700 RPM.
- The calculated fuel rate is between 15 mm³ and 90 mm³.
- DTC runs continuous when the above conditions are met.
The fuel injector balance correction is greater than the calibrated limit.
Yeah, it is stock. I will check the balance rates and compression and see what it's doing. It doesn't have blowby or a dead miss or anything. I guess it could be a valve issue. Anyways, I will check it out better when I get time.
So, a little update. I haven't compression tested it yet. I also can't get my scanner to pull the balance rates. It keeps saying "function not available" on my scan tool. I need to buy an autel...anyways, just for grins and giggles, I replaced those 2 glowplugs. It needed it anyways. Now, no more codes at all, yet. Do you think that it wasn't hitting on those 2 holes when it was cold, because the glowplugs weren't working? Maybe the ecm was seeing a discrepancy when the engine was cold. It is pretty cold outside right now where I live. If they come back, I am going to buy an autel and link up to it. This centech scanner is junk. Oh, and the engine brake works. I discovered that it is different than my 2016. The trans has to be warm before it will work. It works great once it warms up. My 16 model would work right no matter what if I recall. Anyways, I will keep you guys updated and appreciate all the help and advice. You guys have awesome tech info!
Last edited: