Electrical problems with 07 Yukon

[schweg]

I have a 2007 Yukon SLT 5.3L that is having some strange electrical problems.

It had been running perfectly for some time now, no real electrical problems. The other day I went to start it after letting it sit for a couple weeks (the joys of working from home) and there was no power at all, no lights, no power door locks, no dashboard lights. Took the battery out and hooked it up to a charger but it wouldn't take a charge and the diagnostic code from the charger said there was an internal short in the battery. OK, easy fix, just go to Walmart and get a new battery. Put the new battery in and the dashboard lights now come on, but the door locks don't have power, no dome lights, no radio power, and the engine will not turn over. When you turn the ignition to the on position you can her a click from the engine bay.

After reading through the forums I decided it must have a bad negative battery wire. No need to test it out, that seems like a good bet, so off I go to the GMC dealer to get a new cable. Seemed like it would be an easy replacement, but that ground under the radiator is a real pain in the a$$ to get to. Couldn't find any good explanations on the internet how to that but finally realized that it's not so bad if you turn the wheels to the right and go through the wheel well (not exactly easy to do with the engine off). Anyway, finally got the new negative battery cable installed and the new battery hooked up. Still no dome lights, no power door locks, no radio, Noticed that the climate control systems seems to still be working, fan runs, ect. dashboard still lights up but random error messages are starting to pop up. Still hear a click in the engine bay when I turn the key to the on position but the engine does not crank over.

Decided it might be a good idea to plug in my code reader. There was a grand total of 32 codes! Never seen that before. For what it's worth here's the codes it listed:

P0603 Internal control module keep alive memory (KAM) error
P0604 Internal control module random access memory (RAM) error
P0716 Input / turbine speed sensor A circuit range / performance
P0717 Input / turbine speed sensor A circuit no signal
P0722 Output speed sensor circuit no signal
P0752 Shift solenoid A stuck on
P0973 Shift solenoid A control circuit low
P0974 Shift solenoid A control circuit high
P0976 Shift solenoid B control circuit low
P2770 Torque converter clutch circuit high
U0073 Control module communication bus off
P0602 Control module programming error
P0603 Internal control module keep alive memory (KAM) error (not sure why this one is listed twice)
P062F Internal control module EEPROM error
P0722 Output speed sensor circuit no signal
P0723 Output speed sensor circuit intermittent
P0741 Torque converter clutch circuit performance / stuck off
P0742 Torque converter clutch circuit stuck on
P0751 Shift solenoid A performance / stuck off
P0756 Shift solenoid B performance / stuck off
P0757 Shift solenoid B stuck on
P0974 Shift solenoid A control circuit high
P0976 Shift solenoid B control circuit low
P1810 Manufacturer control
P1815 Manufacturer control
P1816 Manufacturer control
P1818 Manufacturer control
P2534 Ignition switch run / start position circuit low
P2764 Torque converter clutch pressure control solenoid control circuit low
P2770 Torque converter clutch circuit high
P3237 DTC definitions not found
P2100 DTC definitions not found

I hate to bring this up, by last year the oil pressure sensor went bad in this car. I ended up taking out the intake manifold to replace it and was surprised to find a big rats nest under the intake manifold. What a strange place to make a home. Looks like the rat had eaten a hole in the foam rubber seal towards the back of engine and had found a way to get in there. Since then I have bought an electric rat zapper and I've caught 7 of those guys in my garage. I'm sort of worried that since my car has been sitting for a couple weeks, maybe they have been nibbling on the wiring harness...

Does this sound familiar to anyone? Any advice on what I should try next would be greatly appreciated. Please save me from randomly replacing parts!

Thanks!
Eric

 

[wjburken]

I have a 2007 Yukon SLT 5.3L that is having some strange electrical problems.

It had been running perfectly for some time now, no real electrical problems. The other day I went to start it after letting it sit for a couple weeks (the joys of working from home) and there was no power at all, no lights, no power door locks, no dashboard lights. Took the battery out and hooked it up to a charger but it wouldn't take a charge and the diagnostic code from the charger said there was an internal short in the battery. OK, easy fix, just go to Walmart and get a new battery. Put the new battery in and the dashboard lights now come on, but the door locks don't have power, no dome lights, no radio power, and the engine will not turn over. When you turn the ignition to the on position you can her a click from the engine bay.

After reading through the forums I decided it must have a bad negative battery wire. No need to test it out, that seems like a good bet, so off I go to the GMC dealer to get a new cable. Seemed like it would be an easy replacement, but that ground under the radiator is a real pain in the a$$ to get to. Couldn't find any good explanations on the internet how to that but finally realized that it's not so bad if you turn the wheels to the right and go through the wheel well (not exactly easy to do with the engine off). Anyway, finally got the new negative battery cable installed and the new battery hooked up. Still no dome lights, no power door locks, no radio, Noticed that the climate control systems seems to still be working, fan runs, ect. dashboard still lights up but random error messages are starting to pop up. Still hear a click in the engine bay when I turn the key to the on position but the engine does not crank over.

Decided it might be a good idea to plug in my code reader. There was a grand total of 32 codes! Never seen that before. For what it's worth here's the codes it listed:

P0603 Internal control module keep alive memory (KAM) error
P0604 Internal control module random access memory (RAM) error
P0716 Input / turbine speed sensor A circuit range / performance
P0717 Input / turbine speed sensor A circuit no signal
P0722 Output speed sensor circuit no signal
P0752 Shift solenoid A stuck on
P0973 Shift solenoid A control circuit low
P0974 Shift solenoid A control circuit high
P0976 Shift solenoid B control circuit low
P2770 Torque converter clutch circuit high
U0073 Control module communication bus off
P0602 Control module programming error
P0603 Internal control module keep alive memory (KAM) error (not sure why this one is listed twice)
P062F Internal control module EEPROM error
P0722 Output speed sensor circuit no signal
P0723 Output speed sensor circuit intermittent
P0741 Torque converter clutch circuit performance / stuck off
P0742 Torque converter clutch circuit stuck on
P0751 Shift solenoid A performance / stuck off
P0756 Shift solenoid B performance / stuck off
P0757 Shift solenoid B stuck on
P0974 Shift solenoid A control circuit high
P0976 Shift solenoid B control circuit low
P1810 Manufacturer control
P1815 Manufacturer control
P1816 Manufacturer control
P1818 Manufacturer control
P2534 Ignition switch run / start position circuit low
P2764 Torque converter clutch pressure control solenoid control circuit low
P2770 Torque converter clutch circuit high
P3237 DTC definitions not found
P2100 DTC definitions not found

I hate to bring this up, by last year the oil pressure sensor went bad in this car. I ended up taking out the intake manifold to replace it and was surprised to find a big rats nest under the intake manifold. What a strange place to make a home. Looks like the rat had eaten a hole in the foam rubber seal towards the back of engine and had found a way to get in there. Since then I have bought an electric rat zapper and I've caught 7 of those guys in my garage. I'm sort of worried that since my car has been sitting for a couple weeks, maybe they have been nibbling on the wiring harness...

Does this sound familiar to anyone? Any advice on what I should try next would be greatly appreciated. Please save me from randomly replacing parts!

Thanks!
Eric

Well.....Welcome to the forum from Iowa. I think you win the contest for most DTC codes in your first post!

Low voltage conditions are hard in these vehicles. I would check absolutely any ground wire connections and power wire connections you can find and make sure they are all solid and not corroded.

 

[Doubeleive]

I agree with Wade you probably have some form of electrical power issue going on.

 

[Jason in DLH]

Definitely won the most codes award! Must have given you a real shock to see the nest!

 

[schweg]

Well.....Welcome to the forum from Iowa. I think you win the contest for most DTC codes in your first post!

Low voltage conditions are hard in these vehicles. I would check absolutely any ground wire connections and power wire connections you can find and make sure they are all solid and not corroded.

Do bite marks count as corrosion?

 

[wjburken]

Do bite marks count as corrosion?

Sure! Corrosion, bite marks, they’re both bad.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics, please.

As folks posted above, check out all ground wires and connections first. Also check for any corrosion on the positive battery cable, particularly close to the battery connector, including under the wire's insulation cover.

 

[schweg]

Here's the new battery with the new negative battery cable installed. The positive terminal looks pretty clean.

I replaced the mega fuse this morning just for kicks:

And here's a pic of the engine ground (the contact is cleaner than it looks here):

 

[89Suburban]

Following this one for sure!!

Holy mackerel!

I had the same issue when I pulled my intake off both foam seals were destroyed I think by a squirrel because there was a peanut shell under there as well. So it’s not unheard of that is a favorite place for animals to dig into on these rigs.

When I reinstalled the intake I left that foam ******** out of there.

HOPEFULLY that shorted battery did no harm to the sensitive components. Did you check all your fuses and relays?

 

[schweg]

Following this one for sure!!

Holy mackerel!

I had the same issue when I pulled my intake off both foam seals were destroyed I think by a squirrel because there was a peanut shell under there as well. So it’s not unheard of that is a favorite place for animals to dig into on these rigs.

When I reinstalled the intake I left that foam ******** out of there.

HOPEFULLY that shorted battery did no harm to the sensitive components. Did you check all your fuses and relays?

Here's a pic of the nest (maybe it was a squirrel?):

 

[89Suburban]

Did you snug up those valley cover bolts while you were in there?

 

[schweg]

Did you snug up those valley cover bolts while you were in there?

Ugh, no I didn't do that. I didn't see any oil leaks up there, so hopefully it's fine for now. Anyway, taking the intake manifold off turned out to be easier than I thought it would be. Only real problem was getting the fuel line disconnect to release. Had to buy three different tools before I found one that would work.

 

[89Suburban]

Ugh, no I didn't do that. I didn't see any oil leaks up there, so hopefully it's fine for now. Anyway, taking the intake manifold off turned out to be easier than I thought it would be. Only real problem was getting the fuel line disconnect to release. Had to buy three different tools before I found one that would work.

IMO that was the worst part was that ******* fuel line connector. I had 2 different tools I bought and they were both useless and I wound up using a pick tools to get it apart somehow.

Also there are 2 crossover steam pipes on in front and one in back that take little gaskets that usually come with the intake kit or the valley gasket kit I can't remember which one but it can't hurt to replace those too whenever you are in there or anybody else goes down this path. Also replaced the oil pressure sensor and the screen under it while I had access available.

 

[thompsoj22]

while someone sits inside and holds the ign in the start "clicking position" tweak on the pos bat cable where the "wire" is crimped to the post adapter and see if there is any change. no starting amps and just voltage to light a few accessories, I would eliminate the positive battery connections before going to other possibilities. As long as the key was off when the battery drained the electronics should be fine.

 

[schweg]

I went ahead and replaced the positive battery cable yesterday and I went through every fuse. Didn't make a difference. The dash board still lights up, climate control system has power. No dome lights, no power in the doors. The headlights work but the high beams don't. No blinkers, fog lights, etc. Power seats work...

Finally wised up and called my buddy that has a tech 2 and we plugged it in last night. Looks like the ECU is fine. Couldn't establish a connection to the BCM. So it looks like that might be the issue. Would at least explain why random tings are still working. I'm looking for a cheap ~$70 used BCM right now to see if it fixes it. Not really sure what I need to look for in a replacement though. Here's a picture of the one I pulled out of the car. Is it important to match the P/N or do I just need to find one that came from a 2007 Yukon? Also does anyone know what the "BLUE" sticker means?

Still not giving up on the rat/squirrel theory, but so far I haven't found anything that looks chewed up.

 

[swathdiver]

I went ahead and replaced the positive battery cable yesterday and I went through every fuse. Didn't make a difference. The dash board still lights up, climate control system has power. No dome lights, no power in the doors. The headlights work but the high beams don't. No blinkers, fog lights, etc. Power seats work...

Finally wised up and called my buddy that has a tech 2 and we plugged it in last night. Looks like the ECU is fine. Couldn't establish a connection to the BCM. So it looks like that might be the issue. Would at least explain why random tings are still working. I'm looking for a cheap ~$70 used BCM right now to see if it fixes it. Not really sure what I need to look for in a replacement though. Here's a picture of the one I pulled out of the car. Is it important to match the P/N or do I just need to find one that came from a 2007 Yukon? Also does anyone know what the "BLUE" sticker means?


View attachment 263516


Still not giving up on the rat/squirrel theory, but so far I haven't found anything that looks chewed up.

When I saw all those codes, BCM was the first thing that came to mind, then the wiring from the tree rat. If the wiring is good, the BCM is the likely culprit. You need the exact part number that your vehicle originally came with and you need to sign up for a subscription over at ACDelco TDS so your buddy can use his Tech-2 to program the BCM to your vehicle. This way all of your options work besides setting the VIN to the computer.

If you clear codes and then get the new ones now that power has been restored, this will help narrow down where the fault lay. I didn't read them all. AllDataDIY will list every code and then you can run the troubleshooter on each one, they should all point to a bad BCM but if they go off in another direction, by all means follow the trail just to be sure.

 

[Joseph Garcia]

If you confirm that the BCM is the source of your issue, then you can order a replacement at Rock Auto. I replaced mine in August, and I was able to reprogram it to my truck using my Tech 2 and the sage advice and guidance from @swathdiver .

The cost from Rock Auto was $172.79, plus a $25 core charge, which was refunded, upon my returning the old BCM to them.

 

[schweg]

Success! I went ahead and replaced the BCM this evening and it started right up. Everything seems to be working fine now (engine cranks over and starts, dome lights, radio, door locks, ect).

I decided to buy a used BCM that was programmed for my VIN instead of trying to program it myself with the tech 2. For no good reason, I bought it from Deering's Sales in MN (320) 403-4000. They answered all my questions over the phone and sent me a programmed BCM with matching P/N within a week. It cost $195 including the programming and shipping. You could probably get one for ~$70 on ebay, but you would have to program it, etc. and I was getting tired of having to borrow my son's car. Case closed.

 

[thompsoj22]

i learned how significant the BCM truly is by watching this thread. Your description of "clicking" from the starter solenoid but not turning over had me convinced it was a simple power/connection to starter issue, maybe even an ignition switch? I couldent have been more wrong, I have a tech2 and threads like this "school me" that vehicles have changed so much, Allways diagnose with test equipment and leave the guessing to those fortunate enough to be troubleshooting a 1967 volkswagon beetle!

 

[iamdub]

Low power, especially a slowly dying battery, does more harm to these things than no power. If it's gonna sit, either keep in on a trickle charger or disconnect the battery altogether.