2008 Tahoe..Parking lights issue..BCM issue?

[cmyhre85355]

I have been chasing a strange electrical issue with my 2008 Tahoe LS. My passenger side parking light will not illuminate. I have changed bulbs several times with no luck. The turn signal works just fine. I did some more digging yesterday thinking perhaps it was the wiring harness to the headlights. I swapped harnesses to the driver side and the parking light worked. However,upon reconnecting the driver side harness I no longer have parking lights on that side either. Turn signal still functions normally on both sides. I’ve checked fuses and relays and everything appears ok. The only other thing I would mention is I have had remote start issues for months where the truck will not start after sitting. I have to manually start with the key and then immediate remote start it. So it’s possible I have a BCM issue somewhere too. That isn’t likely to have any correlation to the aforementioned issue I would assume though


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[TahoeLT10]

I have been chasing a strange electrical issue with my 2008 Tahoe LS. My passenger side parking light will not illuminate. I have changed bulbs several times with no luck. The turn signal works just fine. I did some more digging yesterday thinking perhaps it was the wiring harness to the headlights. I swapped harnesses to the driver side and the parking light worked. However,upon reconnecting the driver side harness I no longer have parking lights on that side either. Turn signal still functions normally on both sides. I’ve checked fuses and relays and everything appears ok. The only other thing I would mention is I have had remote start issues for months where the truck will not start after sitting. I have to manually start with the key and then immediate remote start it. So it’s possible I have a BCM issue somewhere too. That isn’t likely to have any correlation to the aforementioned issue I would assume though


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This would be hard to diagnose without Tech2. There are very cheap way to get your hands on one.

 

[Doubeleive]

check for power at the fuse check and then check for continuity between the fuse and harness/bulb socket. this should point you in the right direction
if you have power at the fuse and not at the socket, then you have a open circuit, you can try making your own ground to the socket and see if the break is the positive or negative, if the break is in the negative then you can just make a ground and you good to go, otherwise you will need to patch in a power wire. or find the break and repair.

 

[Big Mama]

Remote start is very picky at times if there are any inconsistencies.

 

[Big Mama]

This would be hard to diagnose without Tech2. There are very cheap way to get your hands on one.

@TahoeLT10 do you have a discounted source for a Tech2?

 

[TahoeLT10]

@TahoeLT10 do you have a discounted source for a Tech2?

PMd

 

[cmyhre85355]

Been busy with the holidays and was out of town visiting kiddo. Just got back and tested the fuses using a tester light...there’s power to both fuses. Does anyone have a wiring schematic or know where to get one? Thinking this is going to become a pain in the butt to chase down


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[cmyhre85355]

I should add this seems to be an intermittent condition. Sometimes they both work sometimes only the driver side parking light works.


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[Bill 1960]

I have wiring schematics. Is your problem in the front or rear?

 

[cmyhre85355]

Is there any possibility the headlight switch inside the cabin is bad? Just trying to rule things out


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[cmyhre85355]

I have wiring schematics. Is your problem in the front or rear?

Front


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[Bill 1960]

Not sure if these will be legible enough. If it's not I can PM you some PDF's I believe.

 

[cmyhre85355]

Not sure if these will be legible enough. If it's not I can PM you some PDF's I believe.
View attachment 266775 View attachment 266776

Would you mind pm me the PDFs.


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[cmyhre85355]

I’ve been playing around with the Tech 2 (vxdiag plus tech2win on a laptop) when I command an action such as turning on fog lights,should it illuminate on the IP or no? Also I’ve been getting random errors that say i have the wrong vehicle selected.

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[cmyhre85355]

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[cmyhre85355]

This would be hard to diagnose without Tech2. There are very cheap way to get your hands on one.

Any suggestions on inputs to test it with a Tech 2?


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[cmyhre85355]

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[Big Mama]

@swathdiver may have an idea.

 

[Fless]

I see from your first post that you have a 2008 Tahoe LS. In order to select the correct vehicle in the Tech 2 you need to know if it's 2wd or 4wd, along with some of the options (probably like the radio and heater controls, at least it's that way for my '04).

What are your vehicle details and what specifically are you selecting in the Tech 2 menus?

Is the issue long-term or has it just started? Any recent work on the vehicle?

 

[swathdiver]

...when I command an action such as turning on fog lights,should it illuminate on the IP or no?

My experience has been, yes, it should illuminate and on mine at least, the menu in the Tech-2 will have a line for showing that the light is on or off too. Every year's menu, even in the same generation can be different. On mine, I can select "C" for RWD and still access all the BCM features just fine, and it does not see any of the 4x4 stuff. But it is important to select the kind of radio or suspension if it asks to configure the menus properly.