2008 p0340

[OG-Lou]

I just deleted a double post?

I have to re-register if I want to save most post I try to save. Is there a time limit after I check in to make and save a post?

[j5alive]

How many miles on your car? And at what mileage are you in relationship to replacing the timing belt?

Thanks, OG-Lou! My airbag light also came on around the same time and has stayed on, I have not taken it to the dealership to be diagnosed.

My mileage is at 94k and I replaced the timing belt and water pump about 500 miles ago.

[OG-Lou]

J5alive, if that was your first timing belt replacement, you got lucky. On some of these cars the timing belt breaks as soon as 50,000 miles. The owner's manual said to replace the timing belt every 60,000 but I did mine at 50,000.

I have been reading a boat load of forums and read a few places that if the battery voltage gets low, the computer remembers the low voltage and the SRS (air bag light) goes on. But, cars vary so much this might only apply to a few models. Seconly, there is a lot of guessing going on when a person doesn't have a scanner with the right software. Scanners typically say (detects xyz and abc codes in MOST or MANY cars. Most and many leaves big gaps in what a scanner will find.

The government made the car manufactures incorporate what are called "Global Trouble codes" that are emission related. These codes show up on low priced scanners. Special manufacture codes and other codes (not required in the OBD2 requirements) are not in low priced scanners so they don't show up unless you have a more detail capable scanner.

[OG-Lou]

I saw a camshaft sprocket aligning tool made by "MV Tools) on a foreign language Aveo repair video. The video shows a good shot of tensioning the timing belt, which isn't that difficult. Out in the open where it is easier to see how it is done. I don't speak or understand Spanish so I don't know what the guy is actually saying.

https://www.youtube.com/watch?v=XbMDEIEHn1k

The tool first appears at @1:30 and is clearly visible @1:36. I used a couple of search engines and Googled but I didn't find the manufacture. I found what I think was a Mexican company selling the tool for 295 MXN = $14.31 USD and another 200MXN=$9.70 USD I suppose for shipping.

https://laredotools.com/i-aveo-mv-tools-(solo-en-web)

Does anyone have any idea where this tool might be for sale in the USA?

[OG-Lou]

Up Date on my P0340 code and hidden code P0016

I checked the compression again with a different gauge and got 170 to 175 PSI. Just for kicks, I did the compression test with a 3rd gauge and got something to what I got several months ago, which was 140 to 145 PSI. It makes me wonder how accurate some gauges are. All 3 compression gauges were new or almost new.
I was watching a Honda timing belt video and saw that the camshaft sprocket marks to synchronize the timing belt aligned with the top surface of the cylinder head and thought that should applied to an Aveo. I took off the timing belt cover and the valve cover. After rotating the crankshaft to align the camshaft sprocket marks, I laid a bicycle spoke across the top surface of the hear. The end of the spoke was right next to each camshaft sprocket mark so the timing belt job I did over a year and a half ago was done correctly. So what was causing the bucking at low rpm under partial load?
I looked at the belt I installed and the part number wasn't the same as what was listed at Rock Auto. I put on a Gates 76127 I bought with a timing belt kit over a year and a half ago. Rock Auto's part was a GATES T335. Both belts have 127 teeth so the belt most likely wasn't the problem causing the P0340 code that only occasionally turned on the "check engine" (MIL) light. I recently bought the GATES T335 belt so I installed it just because I found it odd I couldn't find an application listing for the Gates 76127 belt.

After the timing belt was installed and tensioned and before I installed the camshaft sensor, I used the bicycle spoke to verify the correct timing of the camshaft position in relationship to each other and the crankshaft and notch by the oil pan. (see pictures). I was installing the replacement cam sensor I put on 1.5 yrs ago and saw that it could be moved a little towards or away from the center of the exhaust camshaft sprocket, so I moved it to the center of the sprocket all I could, thinking the more area of the sensor that the sprocket would pass, the stronger the camshaft sensor position signal would be sent to the computer.

pictures failed to load 2X. Maybe in the next post? 8 more tries=nothing. file size 92k
Just picture a pointer stick laying on top of the head with the pointer touching the cam sprocket timing notches and everything aligns on the intake and exhaust cam sprockets like they are suppose to when the parts are installed correctly.


I buttoned everything up, cleared the generic P0340 and GM special P0016 codes and took the Aveo for a short road test. I was pleasantly surprised and didn't have the slight bucking I have had for the last 6 months.

I do not think the problem was the timing belt part number because the timing marks all lined up with the 76127 belt. My guess is placing the cam sensor closer to the center of the exhaust cam sprocket influenced the camshaft position signal to be stronger so the computer could correlate both the camshaft position signal and the crankshaft position signal to fire the spark plugs at the optimal time and add the optimal amount of fuel.

The P0340 is a general camshaft position error signal and the P0016 is a factory special code indicating the cam and crank signals are not correlated or paired correctly.

The car starts quicker and I had only one slight hesitation under low RPM at moderate load during a 10 mile test run.

During all of this trying to figure out what is the root problem, I bought but didn't need 1 camshaft sensor, 1 inlet air temperature sensor (I didn't have it plugged in all of the way and got a code) A timing belt, pulleys, water pump kit (which I did need and installed at 50K). The other thing is I watched a lot of videos about timing belts and I watched a lot of videos about scanners, lab scopes, and how to use those pieces of equipment. I did buy an $80 Bosch 1050 dongle that works with a tablet or smart phone but only paid $20 used along with a used $199 Harbor Freight ZR13 for $80 at the same time.

The Bosch 1050 has some nice features, comes with several generic codes/capabilities for 1 vehicle but to use it on other cars requires an extra fee. It also requires an extra fee to do some/most ABS and SRS codes on each car or additional car. The ZR13 does more than the Bosch 1050 but not all that much more. The ZR13 found the P0016 code the other scanners didn't find. I also have an older Innova scanner and it only finds some codes.

What also captured my interest was the videos about the General Motors "Tech-2" scanner (used to cost ~$3,000) and the Chinese versions for $300. The Tech-2 was discontinued in 2012 but it had all or most of the problem solving software in the machine. The newer+2012 GM MDI has to be connected to the factory website to do most things where the Tech-2 had the solutions inside the unit stored on a memory card. The connection fee for 3 days for the MDI cost $65 for 3 days and I don't know what dealers pay for the year but it is more than I want to spend.

Well that is all well and good, Tech-2 or MDI BUT it doesn't stop there. A person sometimes needs a "lab scope" which is a precision device that reads voltages and time in great detail. To use a lab scope, a person should have access to other people's scope patterns, which are available but require a subscription=$$ to determine if your pattern on your scope matches other good patterns or shows signs similar bad patterns on other vehicles.

The short story, I think my car is fixed and all it took was moving the camshaft sensor closer to the center of the exhaust camshaft sprocket's center.

[OG-Lou]

Pictures still do not load. Maybe I can make the file size smaller. Anyone know file size limits? I think my pictures are 3.5MB.

I also want to put up some pictures I took of the Bosch 1050 diagnostic screens and some details about the Harbor Freight Zurich ZR13 scanner.

Has anyone used or bought a "Tech-2" scanner. A bunch of guys on a Corvette forum have their own Tech-2 and said they wouldn't be with out one. Re-coding key fobs and doing a few other diagnostic procedures has paid for the $300 Chinese version of the scanner. Not many guys have the MDI because of the connection fees and most have pre 2014 Corvettes or other pre 2014 GM cars and trucks.