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  #1  
Old 07-15-2012, 03:22 PM
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Join Date: Nov 2010
Posts: 6
Default Got a P0128 Code

Found it to say the engine didn't come up to operating temp soon enough.
So I figured the thermostat and got a new one from Auto Zone.
It was made by MotoRad and stamped 187 deg.

Before the thermostat change the gauge would always read at the 1/2 way mark.
After I changed the stat it is now reading between 1/2 and 3/4.
I see lots of guys on here say this is normal but why the drastic change?

My thought is that it was opening to much and cooling to much hence the code?

I've driven it very little but it seems to idle better now that it is running warmer?
Any ideas, it's an 06 H3 with almost 90,000 miles.

Thanks

David
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  #2  
Old 07-15-2012, 05:54 PM
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Location: Oklahoma
Posts: 486
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I have the same thing that comes and goes. I haven't replaced anything on mine yet because nobody can tell me what is causing it
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  #3  
Old 07-15-2012, 06:20 PM
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Location: C-Town
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This is all I could come up with on Identifix..


2006
Customer Concern:
Rough idle, intermittent idle surge, intermittent hard starting. Electronic Control Module (ECM) codes: P0106, P0128, P0300. No misfires at this time, just rough idle. Noted that the Manifold Absolute Pressure (MAP) sensor is 1.8 V at idle, 700 feet above sea level.


Tests/Procedures:
1. Clean the throttle bore.

2. Clean the fuel injectors.

3. Clean the Mass Air Flow (MAF) sensor elements.

4. If same, check Cam Position (CMP) actual vs desired, should be the same, at or near 0.

5. Verify that the Engine Coolant Temperature (ECT) sensor is close to actual, scan data vs infra red temperature gun.

6. If the temperature is OK, replace the thermostat.

7. Check actual MAP sensor voltage on the Green wire, backprobing with a Digital Volt Ohm Meter (DVOM).

8. The MAP sensor should be 1.2 V or less with good idle vacuum at or within 1500 feet of sea level.

9. If actual CMP position is higher than desired, suspect a stuck cam phaser.

10. Change engine oil, use an oil supplement if possible, road test as an attempt to "unstick" the cam phaser.


2007
Customer Concern:Engine Control Module (ECM) DTC P0128

Average Reported Mileage: 87000
Tests/Procedures: 1. Start and run the engine to operating temperature in the shop. Clear the DTC's.

2. Verify the actual temperature of the engine matches the scanner display.

3. If the values match, testdrive the vehicle while monitoring the Engine Coolant Temperature Sensor (ECT).

4. If the actual engine coolant temperature drops to less than 176 F, replace the new defective thermostat.

5. Clean the throttle body assembly.
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  #4  
Old 07-15-2012, 08:00 PM
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Default

I agree 100% with the last post. If problem still occurs then shoot for a thermostat from the dealer or one from UAS
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  #5  
Old 07-17-2012, 03:31 PM
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Location: Boat Town USA MI
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Quote:
Originally Posted by tekstyle View Post
Found it to say the engine didn't come up to operating temp soon enough. So I figured the thermostat and got a new one from Auto Zone. It was made by MotoRad and stamped 187 deg.

Before the thermostat change the gauge would always read at the 1/2 way mark. After I changed the stat it is now reading between 1/2 and 3/4.
I see lots of guys on here say this is normal but why the drastic change?

My thought is that it was opening to much and cooling to much hence the code?

I've driven it very little but it seems to idle better now that it is running warmer? Any ideas, it's an 06 H3 with almost 90,000 miles.
Thanks
David
The obvious is concluding it was stat related, and I don't disagree that your old stat might have been sticking or just might have been at the low end of the possible scale.

The less obvious is causes that are not related to the stat, like a bad fan clutch (assuming yours is still stock) causing the fan to run too often, a bad or dirty MAF, or even a bad/slow O2 sensor. The codes are thrown from overlapping variables, and do not always coincide with reality.

In other words, you still have to diagnose beyond ... "the code says this, so I did that." Clean the MAF with MAF cleaner, it is easy, then see what happens after some miles.
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  #6  
Old 07-17-2012, 09:18 PM
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Location: Tampa,Fl
Posts: 43
Juan Garcia
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sounds to me like vacuum leak.
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  #7  
Old 10-07-2013, 02:23 PM
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Join Date: Feb 2011
Location: Western Michigan
Posts: 32
Default Cam phaser

ressurrecting an older thread here.

Just got the call back from my mechanic
"Sludge on the cam phaser" that they took care of.
I've never heard of that before so was searching here for it, very few posts.

Check engine light came on saturday at the end of a 270mile round trip and I brought it in. It was surging/loping at low speeds on the drive there.

In their opinion I had waited too long between oil changes as I had been going by the OBC generated message rather than the rule of thumb of 3000miles.

Anyone with comments to share regarding "sludge on the cam phaser"?
This is a great, honest local mechanic that i trust pretty well.
On a strange side note, I got fantastic highway mileage on this last tank, go figure!
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  #8  
Old 10-07-2013, 03:29 PM
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There is absolutely no reason to change your oil any more often than the GM Oil Life System tells you to do it.

As to the rest, you did not provide enough information to answer whatever your question is? If you have an 06, and you are asking has anyone ever had a dirty or missing Cam Position Actuator Solenoid screen(s), the answer would be yes. It was a problem more for 06 L52s and earlier Colorado/Canyons than the 07 LLRs and up.

However, I have never heard of that throwing a P0128.
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  #9  
Old 10-07-2013, 06:03 PM
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Join Date: Feb 2011
Posts: 488
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Doc, this might actually be the first time a thread has been resserected and I've been glad about it. Because the post you made back in 2012 here....................................

Doc said:
"The codes are thrown from overlapping variables, and do not always coincide with reality.

In other words, you still have to diagnose beyond ... "the code says this, so I did that.""
..................................I think is the best quote I have seen on this site. and is so true. I've been trying to figure a way to say what you said when I have answered a few people on here before but just didn't know how to put it into words. You said it perfectly.

I remember when we first got our h3 and the first time a code popped up and I did the obvious fixes for it, none of which fixed the problem, then come to find that I had to think outside the box to figure what the real problem was. and I remember thinking how stupid I thought it was to even have these codes if you couldn't figure it out, but now for some crazy reason I can understand that stupid computer...........well sometimes at least, but I do have a much better understanding it, and your post summed it up perfectly.

Anyway, glad I saw that post. Kind of made my day. It's been a week from hell as you can imagine. But anyways, thanks for the smile

and no, I'm not drunk, but man do I wish I was..
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  #10  
Old 10-08-2013, 09:47 AM
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Join Date: Feb 2011
Location: Western Michigan
Posts: 32
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Quote:
Originally Posted by Doc Olds View Post
There is absolutely no reason to change your oil any more often than the GM Oil Life System tells you to do it.

As to the rest, you did not provide enough information to answer whatever your question is? If you have an 06, and you are asking has anyone ever had a dirty or missing Cam Position Actuator Solenoid screen(s), the answer would be yes. It was a problem more for 06 L52s and earlier Colorado/Canyons than the 07 LLRs and up.

However, I have never heard of that throwing a P0128.
I wasn't sure what information was pertinant, I did not realize the subject pertained more to 06's however, I have an 07.
I was hoping to use the thread to further general discussion regarding the Cam Phaser, something I found little about rather than start a new thread. The mechanic did not tell me what the actual code was.
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Old 10-08-2013, 09:47 AM
 
 
 
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Tags
air, check, clutch, code, dtc, fan, flow, h2, h3, hummer, hummerp0128, mass, p0128, sensor, sluggish


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