# p0272 code



## chadtn (Feb 27, 2018)

I believe that if you are facing the front of the car they are numbered left to right. (1 2 3 4) with #4 being the far right injector on the driver's side. My car threw injector specific codes each time I had one die (#2 and #4 on separate occasions). Here is a link to my old thread with part numbers and required tools: Injector Warranty I've also attached the AllData instructions for replacing an injector.

I ended up not needing the slide hammer tool. Mine came out easily and the injector bores didn't need much cleaning. The bolts holding the injector retainer are torque to yield and are supposed to be thrown out. When the second injector died I didn't have a spare on hand and reused that one, but I have since bought spare bolts/injectors. Be very careful when removing the return line on the injectors. The connectors are plastic and easy to break if they get any side loading when you pull up. I ended up having to buy a new return line.

Thanks!

Chad


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## Barry Allen (Apr 18, 2018)

Inline engines are usually numbered from front (the accessory side of the engine) to back (where it mates with the transmission). 

For traverse engines that go sideways, it's the same - count 1 to whatever from the accessories to where it bolts to the transmission.


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## 2017CruzeTD (8 mo ago)

chadtn said:


> I believe that if you are facing the front of the car they are numbered left to right. (1 2 3 4) with #4 being the far right injector on the driver's side. My car threw injector specific codes each time I had one die (#2 and #4 on separate occasions). Here is a link to my old thread with part numbers and required tools: Injector Warranty I've also attached the AllData instructions for replacing an injector.
> 
> I ended up not needing the slide hammer tool. Mine came out easily and the injector bores didn't need much cleaning. The bolts holding the injector retainer are torque to yield and are supposed to be thrown out. When the second injector died I didn't have a spare on hand and reused that one, but I have since bought spare bolts/injectors. Be very careful when removing the return line on the injectors. The connectors are plastic and easy to break if they get any side loading when you pull up. I ended up having to buy a new return line.
> 
> ...


Thank you Chad - this is extremely helpful! I read your post and I having very similar symptoms. I am hoping that I can do it since the dealer wanted closer to $1500 to do one cylinder but I found the part for about $200 with shipping.


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## Barry Allen (Apr 18, 2018)

What is the deal with the fuel trims and other things you mention where something might need reprogramming? Can you just unplug the computer to reset it and let it learn on it's own?

For gasoline vehicles, most or all of them do a lot of continuous self-checking of their injectors to make sure everything is running smoothly and can maintain emissions. Injectors would naturally have small variances, so the computer works to balance them out. It does this by monitoring the O2 sensor in steady-state running (like highway cruising) and a example would be the computer noticing things were running a little bit rich so it slightly trims back injection timing on each cylinder. If it finds one injector that's running a bit rich because it's injecting more fuel than others, it will store that information in memory and will trim that injector timing so that it can balance the fuel load. Same thing for an injector that the computer determines is running lean - it will add more injection timing to have it inject a bit more fuel to balance it out. All this is done within reason, but if the injectors get way out of line due to malfunction or wear, that's when the CEL is illuminated and you've got to replace one or more injectors.

When you yank the battery on a car to try to reset the CEL, that's when the computer has to go through a whole checkup of everything when the battery is reconnected to make sure emissions are working properly. It will go through a baseline setting where the car might be running "not quite right" and after some time the computer will have sorted it all out by doing self diagnostic of injectors and getting them all balanced out if necessary.

Does the computer on our cars do this with the Diesel injectors? The answer is obviously yes, but I'd like to hear more if you can explain how it works on our vehicles.


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## MRO1791 (Sep 2, 2016)

chadtn said:


> I believe that if you are facing the front of the car they are numbered left to right. (1 2 3 4) with #4 being the far right injector on the driver's side. My car threw injector specific codes each time I had one die (#2 and #4 on separate occasions). Here is a link to my old thread with part numbers and required tools: Injector Warranty I've also attached the AllData instructions for replacing an injector.
> 
> I ended up not needing the slide hammer tool. Mine came out easily and the injector bores didn't need much cleaning. The bolts holding the injector retainer are torque to yield and are supposed to be thrown out. When the second injector died I didn't have a spare on hand and reused that one, but I have since bought spare bolts/injectors. Be very careful when removing the return line on the injectors. The connectors are plastic and easy to break if they get any side loading when you pull up. I ended up having to buy a new return line.
> 
> ...



Excellent help here, and your other post on the part and tools, I also will be doing this soon, as my #1 injector is acting up and throwing codes similar to what you described. I'm just under 50K miles, but had an injector replaced before when still under warranty at the dealership. That didn't show any signs, and I did not have a MIL light either. This also is not showing a MIL, but really should be as it is impossible to not notice #1 cylinder skipping a power stoke. It doesn't do it at idle, or light load, and not under heavy load, only slight load or slow acceleration.. quite odd, and even then it's intermittent, sometimes normal, others not.


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## MRO1791 (Sep 2, 2016)

2017CruzeTD said:


> Hello all,
> 
> I have a 2017 cruze TD that has had a intermittent CEL that now has had some drivability issues more recently. Code reader states p0272 which is a cylinder 4 fault. The symptoms I get (usually under light load) is a jerking like one cylinder is starved for fuel/bad injector.
> 
> ...


Now having the same issue, but I have P0263, P0300, P01CC. Cylinder 1 Balance System, Engine Misfire Detected, Cylinder 1 Injection Timing Advance. 

I just ordered the parts and tools, so will be replacing the #1 injector, I already have the GM GDS 2 tool to reset the fuel trims, etc. post replacement. I'm actually surprised this did not request a MIL and CEL light, it was an obvious problem that has to affect MPG, perhaps not emissions as it would be a cylinder without fuel that misfires.. I believe the OBD2 requirement is for emission related faults.


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## MRO1791 (Sep 2, 2016)

Barry Allen said:


> What is the deal with the fuel trims and other things you mention where something might need reprogramming? Can you just unplug the computer to reset it and let it learn on it's own?
> 
> For gasoline vehicles, most or all of them do a lot of continuous self-checking of their injectors to make sure everything is running smoothly and can maintain emissions. Injectors would naturally have small variances, so the computer works to balance them out. It does this by monitoring the O2 sensor in steady-state running (like highway cruising) and a example would be the computer noticing things were running a little bit rich so it slightly trims back injection timing on each cylinder. If it finds one injector that's running a bit rich because it's injecting more fuel than others, it will store that information in memory and will trim that injector timing so that it can balance the fuel load. Same thing for an injector that the computer determines is running lean - it will add more injection timing to have it inject a bit more fuel to balance it out. All this is done within reason, but if the injectors get way out of line due to malfunction or wear, that's when the CEL is illuminated and you've got to replace one or more injectors.
> 
> ...


I'm pretty sure a battery disconnect won't do it, but can't be sure.. it might. That said the procedure to replace injectors has you disconnect the battery negative terminal when replacing the injector... so if that would reset the fuel trims and other items.. it would not likely then have you perform that post install. That information is likely stored in the ECU in non-volatile RAM, so a battery disconnect won't reset it.


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## chadtn (Feb 27, 2018)

MRO1791 said:


> Excellent help here, and your other post on the part and tools, I also will be doing this soon, as my #1 injector is acting up and throwing codes similar to what you described. I'm just under 50K miles, but had an injector replaced before when still under warranty at the dealership. That didn't show any signs, and I did not have a MIL light either. This also is not showing a MIL, but really should be as it is impossible to not notice #1 cylinder skipping a power stoke. It doesn't do it at idle, or light load, and not under heavy load, only slight load or slow acceleration.. quite odd, and even then it's intermittent, sometimes normal, others not.


I've been trying to share as much information as I can. I love the car, but dread letting people who have probably never even seen one before work on it. I'd rather do it myself so I know what I jacked up instead of paying someone to learn on my car and guessing what they screwed up. heh..

At 78k miles my slave cylinder died Friday, two hours from home, on the interstate in Atlanta rush hour traffic, and on Memorial Day weekend. Had to pay a wrecker $150 to tow it eight miles to my hotel. I was quoted $2000 to tow it back home if I pay in cash. I had to call all of my truck friends and beg them to spend Memorial Day hauling me home.

I'll try to write up something similar on the slave cylinder replacement, but it's going to take a while to get parts again. I started reading over the replacement procedure and there are a shocking amount of TTL bolts used on practically everything (motor mounts, transmission mounts, flywheel, slave cylinder, and more!!). I'm going to do some research on if they are actually necessary, or if I can just match them up to hardened bolts and torque normally. There are eight TTL bolts just on the flywheel and gmpartsdirect.com wanted over $8 a bolt!

Thanks!

Chad


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## MRO1791 (Sep 2, 2016)

chadtn said:


> I've been trying to share as much information as I can. I love the car, but dread letting people who have probably never even seen one before work on it. I'd rather do it myself so I know what I jacked up instead of paying someone to learn on my car and guessing what they screwed up. heh..
> 
> At 78k miles my slave cylinder died Friday, two hours from home, on the interstate in Atlanta rush hour traffic, and on Memorial Day weekend. Had to pay a wrecker $150 to tow it eight miles to my hotel. I was quoted $2000 to tow it back home if I pay in cash. I had to call all of my truck friends and beg them to spend Memorial Day hauling me home.
> 
> ...


Chad, 
Your efforts are appreciated. I have 3 Gen 2s and a Gen 1 all diesels in the family fleet, so knowing how to fix them is quite a big deal for me. The Clutch Slave Cylinder had some kind of design defect. I had quite the write up on my manual with a Dual Mass Flywheel (DMF) failure at just over 12K miles, fortunately repaired under warranty, which included the new design slave cylinder. My dealership made note of the new part number for that part.. as in they knew of the issue. 

When they replaced my DMF they were able to do it without pulling the engine, but had the entire left front wheel and associated parts out to remove the transmission, it is my understanding that is what has to be done to get to that slave cylinder. I only have 1 car that is manual, the others are automatic, so I'm going to have to figure out the fluid and filter replacement soon for the Gen 2s, already did the Gen 1, though it might be getting close for the next interval 

I could not find the injectors in stock on the GM parts sites, but found 3 on Amazon, I ordered 2, since one failed, and with 3 cars.. certainly likely another will fail and I don't want to be waiting for parts for a long time.


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## chadtn (Feb 27, 2018)

MRO1791 said:


> Chad,
> Your efforts are appreciated. I have 3 Gen 2s and a Gen 1 all diesels in the family fleet, so knowing how to fix them is quite a big deal for me. The Clutch Slave Cylinder had some kind of design defect. I had quite the write up on my manual with a Dual Mass Flywheel (DMF) failure at just over 12K miles, fortunately repaired under warranty, which included the new design slave cylinder. My dealership made note of the new part number for that part.. as in they knew of the issue.
> 
> When they replaced my DMF they were able to do it without pulling the engine, but had the entire left front wheel and associated parts out to remove the transmission, it is my understanding that is what has to be done to get to that slave cylinder. I only have 1 car that is manual, the others are automatic, so I'm going to have to figure out the fluid and filter replacement soon for the Gen 2s, already did the Gen 1, though it might be getting close for the next interval
> ...


I've been keeping two new spare injectors in my "inventory" as well. heh..

The transmission definitely has to come out to replace the slave cylinder. When I get back home I will dive into reading up on it some more. If the whole axle assembly ends up having to be removed to get the transmission out, then it's calling for several specialty tools I'll have to buy. If they can stay in place and just need to be separated from the transmission, then it doesn't require any tools that I don't have already.

Thanks!

Chad


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## Barry Allen (Apr 18, 2018)

MRO1791 said:


> which included the new design slave cylinder. My dealership made note of the new part number for that part.. as in they knew of the issue


There was a changed slave cylinder, with a new part number?

Nothing I could ever find showed that anything was changed. My slave cylinder failed TWICE, the second time after just 22,000 miles from the first repair.


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## Barry Allen (Apr 18, 2018)

I looked at more information online about the various parameters of these injectors and it's interesting to see that they are rated at the factory for flow rate and assigned fuel trims to tell the engine computer a starting point. Back in the day of mechanical injection the injectors would be manually checked and you'd get them within an acceptable operating pressure range. If you got all the injectors in one engine operating within about 10% of each other, that was "good enough." Now we have it to where the injectors can be dialed in to about 1% of each other. The future is amazing to live in.


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## MRO1791 (Sep 2, 2016)

Barry Allen said:


> There was a changed slave cylinder, with a new part number?
> 
> Nothing I could ever find showed that anything was changed. My slave cylinder failed TWICE, the second time after just 22,000 miles from the first repair.


Yes, they said it was a new part number, I'll have to get the paperwork and grab that number, they listed all the parts they used on the job.


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## 2017CruzeTD (8 mo ago)

As an update - I have replaced the injector (#4) that was suppose to be bad however I still have the same symptoms. CEL is on with the same code and the jerking that occurs (about at 45mph near 2K RPM) persists. Anyone else have any ideas? may have to finally take it in the the dealer


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## Cruz15 (Mar 17, 2016)

2017CruzeTD said:


> As an update - I have replaced the injector (#4) that was suppose to be bad however I still have the same symptoms. CEL is on with the same code and the jerking that occurs (about at 45mph near 2K RPM) persists. Anyone else have any ideas? may have to finally take it in the the dealer


I would need pics of the connector, is there a seal at the end to keep water out, Could excessive oxidation on the connectors cause such code? I will try and have a look tomorrow under the hood.


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## aaronmk4 (8 mo ago)

2017CruzeTD said:


> As an update - I have replaced the injector (#4) that was suppose to be bad however I still have the same symptoms. CEL is on with the same code and the jerking that occurs (about at 45mph near 2K RPM) persists. Anyone else have any ideas? may have to finally take it in the the dealer


So looking into the code on GM Service Information, here is the verification/diagnosis for your P0272 code. You may want to try a compression test tool and/or leak down test tool to see if cylinder #4 has comparable compression to the other cylinders. If within spec or the same as other cylinders, then your problem may lie with the injector. Wouldn't be the first time I've seen a bad part out of the box, unfortunately.


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