OBD2 does not connect

Tiny
WALTHER-ANNA VON EINIK
  • MEMBER
  • 2004 CHEVROLET ASTRO
  • AUTOMATIC
  • 132,000 MILES
Good day, I need a help with OBD2 scanner problem. I try to connect to my van, but it connects to OBD2, show connection lights and then app shows that it cannot establish a connection with the car. What is can be? This scanner works with our other vehicle so I know it works. Can you help what it can be? Also, can you tell what scanners are good? Easy and truthful? Thank you!
Sunday, April 29th, 2018 AT 9:41 PM

19 Replies

Tiny
HARRY P
  • MECHANIC
  • 2,295 POSTS
If you are using one of those Bluetooth scanners that you get from eBay, it is the problem. From what I have seen, they do not do too well with Chevrolet's. Also, if your cigarette lighter is not working, check the fuse for it, as that fuse also powers the OBD2 connector. Let us know.
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Monday, April 30th, 2018 AT 4:12 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good morning.

Auto Tell is a good tester. It is simple and will give you advanced data as well that you need. Codes never identify bad parts just failed systems.

Check for power to pins 1 and 16 on the connector at the car. 16 is power and 1 is ground. You can use a voltmeter to check. If this is good, then it can be either a serial data line issue or the PCM itself.

Roy.
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Monday, April 30th, 2018 AT 4:13 AM
Tiny
WALTHER-ANNA VON EINIK
  • MEMBER
  • 12 POSTS
Thank you so much, I will do these steps and let you know!
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Monday, April 30th, 2018 AT 11:07 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
You are welcome.

Keep us updated.
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Tuesday, May 1st, 2018 AT 3:40 AM
Tiny
WALTHER-ANNA VON EINIK
  • MEMBER
  • 12 POSTS
I am still fixing it. I did not have the time to check it. But I have one more question, I have a problem with my ignition lock, it jams a little when starting. Can I fix it or buy another one?
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Wednesday, May 2nd, 2018 AT 1:24 PM
Tiny
ASEMASTER6371
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Try spraying some WD40 in the cylinder and see if that helps. Otherwise you will need to replace it.

Roy
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Wednesday, May 2nd, 2018 AT 1:37 PM
Tiny
HARRY P
  • MECHANIC
  • 2,295 POSTS
You can also spray the key down and then put it in the cylinder.
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+1
Wednesday, May 2nd, 2018 AT 6:59 PM
Tiny
WALTHER-ANNA VON EINIK
  • MEMBER
  • 12 POSTS
Thank you all! I started to check pin connector and I have a question. Here is a picture. What I this yellow connector? And those taped block? I were looking for any switch maybe, too, but found these things. Maybe something wrong with this taped black block? And what is this yellow connector?
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Thursday, May 3rd, 2018 AT 3:47 PM
Tiny
ASEMASTER6371
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I am sorry, there is no picture attached. Can you send it again so we can view it?
Roy
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Thursday, May 3rd, 2018 AT 3:50 PM
Tiny
WALTHER-ANNA VON EINIK
  • MEMBER
  • 12 POSTS
Sorry, I thought it was sent. Here it is.
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Thursday, May 3rd, 2018 AT 4:16 PM
Tiny
WALTHER-ANNA VON EINIK
  • MEMBER
  • 12 POSTS
Also, I have a question regarding maybe security wire. I cannot start the van, and I am very confused because I open doors with this remote key without the problem. What it can be and what do I need to check? Thank you!
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Thursday, May 3rd, 2018 AT 4:19 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Yellow connectors indicate air bag circuits. Do not touch them for the risk of inflating the airbag.

Not sure of the other piece. Let me check and see if I can identify it.

What security wire?

Roy
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Thursday, May 3rd, 2018 AT 4:25 PM
Tiny
WALTHER-ANNA VON EINIK
  • MEMBER
  • 12 POSTS
Thank you for any help. About wire, I just do not know what to do with it and thought maybe there are any kind of security wire or switch. Why does the car not start?
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Thursday, May 3rd, 2018 AT 4:34 PM
Tiny
WALTHER-ANNA VON EINIK
  • MEMBER
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We do not have a connection with the previous owner and he told us that the car was I working condition until we bought it. But now we cannot start it.
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Thursday, May 3rd, 2018 AT 4:35 PM
Tiny
ASEMASTER6371
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Okay, does the starter work?

https://www.2carpros.com/articles/how-a-starter-and-solenoid-works
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Thursday, May 3rd, 2018 AT 4:37 PM
Tiny
WALTHER-ANNA VON EINIK
  • MEMBER
  • 12 POSTS
Yes, everything moves but does not start. And I do not hear that gas pump works. No sound. We have replaced crankshaft sensor but still no changes. We thought maybe it is a wire lime in the YouTube video I will attach it in the next message.
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Thursday, May 3rd, 2018 AT 5:20 PM
Tiny
WALTHER-ANNA VON EINIK
  • MEMBER
  • 12 POSTS
Https://www.youtube.com/watch?v=xnmBSmLlpCM
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Thursday, May 3rd, 2018 AT 5:26 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
I think we should back up and see why there is no communication which is job one. Here is the wiring diagram for the ALDL connector you should check all of the fuses as well:

https://www.2carpros.com/articles/how-to-check-wiring

Check the fuse (aux power).

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If everything checks out it sounds like the PCM is bad and needs to be replaced which you can do by getting a used one and plugging it in, (this sometimes works) if not you will need to have it programmed.

Check out the diagrams (below).

Let us know what happens and please upload pictures or videos of the problem.

Cheers, Ken
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Sunday, May 6th, 2018 AT 4:46 PM

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