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Monday, May 6th, 2019 AT 6:29 PM
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Hope you got it going your way.
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Engine will not crank over?
LAWYN
- MEMBER
- 6 POSTS
- 2005 CHEVROLET MONTE CARLO
- 3.4L
- V6
- FWD
- AUTOMATIC
- 110,000 MILES
Vehicle was started and stopped about 6 times. It then sat for about 2 hours, when I went to leave the dash lights flickered and a "relay symphony"sound came from under the dash and the driver side fuse box. Checked battery, it is 12.5V. Car will not start so can not test further. All fuses are good and all relays tested good. Changed the ignition switch, did not help. Had BCM repaired (company I used said they repaired it) and car still doing the same thing. Code reader can not get codes, the screen flickers with the dash lights. Any ideas on what might be the problem?
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Monday, May 6th, 2019 AT 6:29 PM
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Are you saying it cranks good but won't start or it won't even crank? Did you check for voltage at applicable fuses or relays, use a testlight or digital multimeter.
Can you communicate with computer? If not that's where I would start. Can you force the computer to set a code just as a test? Also, with key on, check for ref voltage at any sensor that uses a ref voltage, if no ref voltage, go from there.
Does the starter crank ok?
Anybody else with any ideas, jump in.
Can you communicate with computer? If not that's where I would start. Can you force the computer to set a code just as a test? Also, with key on, check for ref voltage at any sensor that uses a ref voltage, if no ref voltage, go from there.
Does the starter crank ok?
Anybody else with any ideas, jump in.
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Monday, May 6th, 2019 AT 6:29 PM
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LAWYN
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Will not crank. I put the key in the ignition and it "freaks out". Can not link with code reader.
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Monday, May 6th, 2019 AT 6:29 PM
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Right now, I think you have a computer problem. I'd have to check voltage and ground circuits at computer, go from there. Maybe the computer is trying to reset for some reason.
We can usually crank the starter, but, that doesn't mean it will start. The computer grounds the crank relay.
Did you try taking the negative battery cable loose for a few minutes and then reconnect, see if it helps?
We can usually crank the starter, but, that doesn't mean it will start. The computer grounds the crank relay.
Did you try taking the negative battery cable loose for a few minutes and then reconnect, see if it helps?
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Monday, May 6th, 2019 AT 6:29 PM
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Just to add, I'd still have to double check the battery and connections.
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Monday, May 6th, 2019 AT 6:29 PM
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LAWYN
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Yes I removed negative battery cable re-attached but there was no change.
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Monday, May 6th, 2019 AT 6:29 PM
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LAWYN
- MEMBER
- 6 POSTS
Going to check grounds soon. I will keep you updated. Thanks for the ideas.
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Monday, May 6th, 2019 AT 6:29 PM
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LAWYN
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- 6 POSTS
I was told that I might have a ground fault in clstr/BCM/DLC circuit. How can I check this to find out? Where is the ground for this circuit located?
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Monday, May 6th, 2019 AT 6:29 PM
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The ground for the instrument cluster is A4 in the diagram. Take connector loose from instrument cluster, use a test lite connected to battery voltage, touch the A4 terminal on the wiring harness connector, if the lite comes on, the ground is good.
At your datalink connector, where you plug in a scanner or code reader, pin 16 is hot all the time. Check for voltage. Pin 4 and 5 are grounds, check those also.
At your datalink connector, where you plug in a scanner or code reader, pin 16 is hot all the time. Check for voltage. Pin 4 and 5 are grounds, check those also.
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Monday, May 6th, 2019 AT 6:29 PM
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This is your data link connector.
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Monday, May 6th, 2019 AT 6:29 PM
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LAWYN
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Thank you so much for the info. I will let you know what happens.
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Monday, May 6th, 2019 AT 6:29 PM
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No problem, have a good day.
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Monday, May 6th, 2019 AT 6:29 PM
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