Dead Batterry

[champwhiteitr]

check the ground strap on the (electric) power steering

Double check and it’s bolted down

 

[champwhiteitr]

Did you make sure the ignition was not in the on position when the new battery was installed? You shouldn't need it but do you have access to a scan tool?

Ignition was off when battery was changed and I scanner shows communication faults

 

[Doubeleive]

Double check and it’s bolted down

ok, disconnect both the battery and power steering ground, clean the power steering ground (wire brush, etc) then reconnect it and then the battery carefully if you are sitting there wiggling the cables on the battery while tightening that can cause the communication errors (bad-handshake between the various modules).
the k2's and later are even more prone to electrical faults than previous generations.
sometimes if the errors persist you can try resetting the bcm with a code reader, just tell it to clear codes even if there are none. that resets the bcm even if there are no codes.
It might even take 2-3-4 tries. then if the issue persist's seek a shop/dealer for a deeper diagnostic.

 

[champwhiteitr]

ok, disconnect both the battery and power steering ground, clean the power steering ground (wire brush, etc) then reconnect it and then the battery carefully if you are sitting there wiggling the cables on the battery while tightening that can cause the communication errors (bad-handshake between the various modules).
the k2's and later are even more prone to electrical faults than previous generations.
sometimes if the errors persist you can try resetting the bcm with a code reader, just tell it to clear codes even if there are none. that resets the bcm even if there are no codes.
It might even take 2-3-4 tries. then if the issue persist's seek a shop/dealer for a deeper diagnostic.

Where is the power steering ground located?

 

[Doubeleive]

Where is the power steering ground located?

I thought there was a ground strap on the power steering but there is a plug to check and apply some dielectric grease and possibly some others to look at it, referenced in this video
but I would check around the battery mostly since that what was touched, be sure all those fusible links on the battery top plate and clean snug and make sure no wires got damaged

 

[champwhiteitr]

I thought there was a ground strap on the power steering but there is a plug to check and apply some dielectric grease and possibly some others to look at it, referenced in this video
but I would check around the battery mostly since that what was touched, be sure all those fusible links on the battery top plate and clean snug and make sure no wires got damaged

Thank you I will check this!!!

 

[champwhiteitr]

Doesn't your Fluke show any significant digits? With the battery unloaded (disconnected and having rested a few hours) it reads 13.0vDC? No tenths of a volt?

Tested again with new meter and I got 14.6 running and 12.7 off

 

[Rygrego]

Ignition was off when battery was changed and I scanner shows communication faults

Have you checked the underhood ECU fuse? That would give the lack of communication error messages.

 

[Doubeleive]

Tested again with new meter and I got 14.6 running and 12.7 off

voltage is fine, is the error still showing? did you try a clear codes with a odb reader?

 

[champwhiteitr]

voltage is fine, is the error still showing? did you try a clear codes with a odb reader

voltage is fine, is the error still showing? did you try a clear codes with a odb reader?

Lights stay on even after clearing with scanner. For some of the modules it says no communication

 

[champwhiteitr]

Have you checked the underhood ECU fuse? That would give the lack of communication error messages.

Do you happen to know which fuse that is?

 

[Doubeleive]

Lights stay on even after clearing with scanner. For some of the modules it says no communication

did you check the fusible links on the top of the battery panel?

 

[Rygrego]

Do you happen to know which fuse that is?

The lid of the fuse box will list it. You never said your model year. Check continuity on any fuse with ECU or ECM in the labeling.

 

[champwhiteitr]

did you check the fusible links on the top of the battery panel?

I replaced that whole piece

 

[Doubeleive]

I replaced that whole piece

only other thing I can think of is there is a wiring harness that runs between the battery and the right side fender, if that was pinched or the connector messed with then maybe that could be it, but otherwise you might have to take it in and have the dealer put a scope on it, If you do that be sure anything aftermarket (electrical) is unplugged or removed because the way they diagnostic these things that will interfere with the process and be the first thing they blame it on.
diagnostic's with a scope run about $180 per hour but a good tech should be able to find it in less than 2 hours.
For whatever reason sometimes on these k2's people have reported having to have modules reprogrammed when the battery as been replaced, sometimes there is a no start issue, sometimes it's the bcm or other modules. just what I have seen reported in the past.

 

[champwhiteitr]

The lid of the fuse box will list it. You never said your model year. Check continuity on any fuse with ECU or ECM in the labeling.

Sorry it’s a 2016 Yukon 5.3, I be checked every fuse and still no luck

 

[champwhiteitr]

only other thing I can think of is there is a wiring harness that runs between the battery and the right side fender, if that was pinched or the connector messed with then maybe that could be it, but otherwise you might have to take it in and have the dealer put a scope on it, If you do that be sure anything aftermarket (electrical) is unplugged or removed because the way they diagnostic these things that will interfere with the process and be the first thing they blame it on.
diagnostic's with a scope run about $180 per hour but a good tech should be able to find it in less than 2 hours.
For whatever reason sometimes on these k2's people have reported having to have modules reprogrammed when the battery as been replaced, sometimes there is a no start issue, sometimes it's the bcm or other modules. just what I have seen reported in the past.

Thank you and I’ve come to the point I’m just going to take it in to a dealer. I’ve tried a lot of things with no success. The truck still drives fine it’s just the lights bother me. But it’s something that can wait.

 

[Doubeleive]

Thank you and I’ve come to the point I’m just going to take it in to a dealer. I’ve tried a lot of things with no success. The truck still drives fine it’s just the lights bother me. But it’s something that can wait.

good luck, please report back and let us know what it ended being whenever it gets done. Perhaps that info will help someone else down the road.

 

[N9Phil]

I assume that when you say that you replaced the battery with another one that it was a brand new battery. The only true way to check a battery is with a load test. I have had batteries that voltage tested good after charging but as soon as you put a load test on them they failed. Some cars after changing the battery have to have their electronics reset. Welcome to the word of computers controlling almost everything.

 

[DGsHoe]

• Starter Relay / Fuse
  • In the under-hood fuse block:
    • Starter Relay (labeled STRTR or CRNK)
    • Fuses for ECM and IGN
  • Sometimes pulling the relay and reseating it fixes poor contact.
    
• Neutral Safety Switch (Range Sensor)
  • Try starting in Neutral instead of Park. If it cranks in Neutral, the switch is worn.
    
• Security System (PassKey/PassLock)
  • If the Security or Padlock light is flashing on the dash, the immobilizer may have reset when the battery died.
  • Relearn procedure:
    1. Turn key to ON (do not start).
    2. Wait ~10 minutes until the security light stops flashing.
    3. Turn key OFF for 5 seconds.
    4. Repeat 2 more times (total ~30 minutes).
    5. Try to start.