Post Reply 
 
Thread Rating:
  • 0 Votes - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
2006 CTS Electrical Issues
01-16-2015, 01:31 PM
Post: #1
2006 CTS Electrical Issues
I brought a 2006 cts..it was skipping really bad i put it on diagnostic machine..advised injector 1 and 2 misfire. Changed all injectors and coils..put back on machine and still the same codes..I got the Heads redid , still codes show inj 1 and 2 misfire..put in a new motor, still show same codes..could this be an ECM issue or a sensor issue. If a sensor, which one? Please help me I'm like $5000 invested in this car and its still skipping....
Find all posts by this user
Quote this message in a reply
01-16-2015, 09:59 PM
Post: #2
RE: 2006 CTS Electrical Issues
Not to over look the obvious, but based on your post you are jumping around a bit instead of doing diagnosis in a logical order, with basics first.

That said, if the compression is good then the engine is probably ok mechanically. You have done what seems to be the next logical step with replacement injectors and ignition parts, but didn't mention spark plugs. (could it be that simple?)

Now, it "could be" many things but the next step I would do is clear the ECM codes and see what new ones come back, then post those codes here. The exact codes will help us sort out things and may even point directly to an issue with a bad wiring harness, stuck EGR, or a major vac leak. (cracked manifold?) Basically I feel we are looking for something that was transfered from the old engine to the new engine. If your scanner is fancy enough it may be able to read info from the crank sensor to see if the trigger pulse is there on all cyls. If it's just a code reader then maybe your next step is to get with someone who has better equipment. Spending $100 for a GOOD diagnosis could wind up being priceless!
Find all posts by this user
Quote this message in a reply
01-17-2015, 07:55 AM
Post: #3
RE: 2006 CTS Electrical Issues
I agree with what Rupe is telling you. There is one more thing I would like to add to his request for information. If you have the original codes; or can get them, please post them here along with the new codes. Post code NUMBERS; i.e., P0301 & P0302, not someone else’s interpretation of what they mean. If you don’t have the original codes you could have the computer scanned, record all of the codes, post those codes here for review, & have the computer cleared. Run the car until the CEL comes on and repeat the procedure. That way we can compare older data with current data. Also keep in mind that a high end scanner can access more systems than the simple Code Readers. So; as Rupe mentioned, paying for a complete scan with a high end scanner may turn up things that a code reader has missed. That’s why I also stress Recording & Posting ALL codes from All systems.

Thanks for using the forum,
Garner

Interested in Mining? Look here: Coal Mining, PA
Visit this user's website Find all posts by this user
Quote this message in a reply
01-17-2015, 03:48 PM
Post: #4
RE: 2006 CTS Electrical Issues
Thanks guys, what code scanner should I go purchase? Give me a few brand names of the best scanners on the market so I can go purchase it.
Find all posts by this user
Quote this message in a reply
01-17-2015, 05:05 PM (This post was last modified: 01-19-2015 01:07 AM by Rupe.)
Post: #5
RE: 2006 CTS Electrical Issues
General purpose code readers start at well below $100 and fancy ones can range to near $5,000. Buying one of the facny gadgets is something that is only done in a good sized shop due to the "pay back" period and the need to update the software on a regular basis. ($500 / year?) Most DIY types buy something in the $200 range that will cover the cars they own or expect to own soon, and if they get in over their heads on a job they understand they either need to fork out for a fancy unit or pop to have a shop do the diagnosis. It's a matter of weighing out the odds on what you will save versus when you spend... AND... knowing what to do with the info the tool provides. Personally (and after over 40 years in the business) I know my limits and still take a vehicle to the dealer once in awhile because it's faster / cheaper than trying to bang my head in a small fleet shop. For what I do the shop owns two scan tools. One is for engine / driveline and the other is for ABS units. They are worth their weight in gold but these cheaper units will need replacement soon because there is no new software available and they top out on the 2008 model year. See where this is going?

BTW, the brand my shop owns is Actron. They are very user friendly and fairly sturdy. Maybe Garner has another suggestion? If you are computer savvy there are more options out there for lap top programs and cables that are fairly cheap but you need to be a whiz kid and still have to know what the numbers on the screen mean. I suspect you can go that route for under $500.
Find all posts by this user
Quote this message in a reply
01-18-2015, 04:52 PM
Post: #6
RE: 2006 CTS Electrical Issues
Here are a list of the codes its read: po300, po301, po302, po201, po202... These are the same codes that the car be reading since I brought it and the same ones reading after I've done on this work on the car...
Find all posts by this user
Quote this message in a reply
01-18-2015, 06:13 PM
Post: #7
RE: 2006 CTS Electrical Issues
P0300 is a ramdom misfire... possible causes...
- Faulty spark plug (s)
- Faulty ignition coil (s)
- Clogged or faulty fuel injector (s)
- Intake air leak
- Fuel injectors harness is open or shorted
- Fuel Injectors circuit poor electrical connection
- Ignition coils harness is open or shorted
- Ignition coils circuit poor electrical connection
- Insufficient cylinders compression
- Incorrect fuel pressure

In my experience, checking fuel pressure is a high priority for a typical random misfire but since we are limited to two cyls let's skip that for now.

P0301 is cylinder 1 misfire... possible causes...
- Faulty spark plug 1
- Clogged or faulty fuel injector 1
- Faulty ignition coil 1
- Fuel injector 1 harness is open or shorted
- Fuel injector 1 circuit poor electrical connection
- Ignition coil 1 harness is open or shorted
- Ignition coil 1 circuit poor electrical connection
- Insufficient cylinder 1 compression
- Incorrect fuel pressure
- Intake air leak

P0302 is the same as P0301 but cyl #2.

P0201 is fuel injector circuit condition. (open or shorted) The PCM has detected a fault in the injector or the wiring to the injector.
Since all the injectors in a bank share a ground it's probably not a grounding issue. In your case the misfire is in both banks if you follow the logic.

P0202 is the same but cyl #2.

Here's what I would do...
You didn't mention new plugs so that's a MUST just to rule out the easy stuff.
You did mention coil packs but an easy test would be to swap them to another cyl and see if the problem follows the parts or stays the same.
You can do similar with the injectors by swapping their position.
You can try using an ohm meter to verify individual injectors for open circuits.
While you have the harness plugs off you can check for both power and ground to the coil packs AND the injectors during cranking. Use a "noid light" which is a rather inexpensive test light just for that purpose. You will likely need a helper to crank while you watch.

If the noid light shows the circuits as good you can rule out issues with the PCM and the harness then concentrate on the injectors or coil packs again. If the noid light doesn't respond then examine the harness or even do a pin by pin test with an ohm meter. Based on todays cheap prices of remanufactured ECM / PCM replacements I would lean toward replacing that if other tests don't find anything.
Find all posts by this user
Quote this message in a reply
Post Reply 


Forum Jump:


User(s) browsing this thread: 1 Guest(s)