Remote Start Troubleshooting

[Tozan]

Did you ever check if your rear defroster is working and the rear glass is 150% shut?

Any trace of an open door, hood, lift gate or hatch glass will abort the start sequence.

Interesting how might the rear defroster affect it.? My defroster is disconnected... Does the defroster affect the fob reception? BTW my auto start works but, I have to be pretty close to the truck to get the fob functions to work now...

 

[petethepug]

Any fault in the rear lift gate / glass or alarm defeats the remote start. Broken lift glass defrost wires are known to trigger the alarm or DTC after the vehicle is locked.

A few have said keying on the ignition without starting the vehicle 2x will undo the R/S lock out triggered by too many failed remote start attempts. Starting the vehicle with the key after that will undo the remote start lockout.

Another tip is to hit the lock button on the fob until it honks, then hold down the R/S button.

Verify that remote start is turned on in the center console display (DIC).

The remote start function in the tech2 is located in the same section as window up/down, door lock/unlock. Again, my Tech2 was stolen so I’m blind guiding you.

 

[swathdiver]

James - I have just two codes that consistently recur: 1) I have an aftermarket radio so there is no communication with that and 2) there is a code related to the in-door courtesy lights that my LT does not have. I believe there is a TSB that says the code is normal and to ignore it. I have cleared all codes and immediately tried the remote start to no avail.

In the BCM section there is another BCM menu and within that one towards or at the bottom is one called anti-theft or something like that. When you click on that it will give reasons for the alarm going off or the remote start not working if memory serves. I went outside to do it today twice but forgot each time. I can try again tomorrow if I'm not distracted.

 

[DaveO9]

Any fault in the rear lift gate / glass or alarm defeats the remote start. Broken lift glass defrost wires are known to trigger the alarm or DTC after the vehicle is locked.

A few have said keying on the ignition without starting the vehicle 2x will undo the R/S lock out triggered by too many failed remote start attempts. Starting the vehicle with the key after that will undo the remote start lockout.

Another tip is to hit the lock button on the fob until it honks, then hold down the R/S button.

Verify that remote start is turned on in the center console display (DIC).

The remote start function in the tech2 is located in the same section as window up/down, door lock/unlock. Again, my Tech2 was stolen so I’m blind guiding you.

Tried the key on x2 reset tip tonight - no good. Darn I was really hoping it would be something simple like that.
My rear defrost has not worked since I bought the rig. When I bought it the P/S coiled wire was detached. I glued it on with the conductive glue kit available online - I thought I was getting conductivity to the grid, but I recall this winter it seemed like it was still not working. It's on my list to do some more troubleshooting. But it's never worked and remote start did when I first bought the rig. It's possible it could be the back glass, but there's a DIC message that definitely lets me know if it's not latched.

In the BCM section there is another BCM menu and within that one towards or at the bottom is one called anti-theft or something like that. When you click on that it will give reasons for the alarm going off or the remote start not working if memory serves. I went outside to do it today twice but forgot each time. I can try again tomorrow if I'm not distracted.

I thought I found all the remote start menus - there was the one that said I was getting an ECM abort, but I never found a menu item that said why it was aborting. I was just looking at my phone and it looks like I erased the screen shots I took, so maybe I'll try it again.

Could R/S not working have anything to do with the backup sensor system? My system is working (mostly) normally now, but I've had some troubles with it in the past. I thought the issue was with the module so I replaced that with a used one. When I realized that the module was not the problem, I went back to my original module, because with that module you get an error if it doesn't match the VIN. So no issue, but possibly some residual effects from doing that swap? And I replaced two of the original sensors with used OEMs from eBay. System works great now, but it seems overly sensitive, getting triggered from the side of my garage door opening when I back out. And sometimes when I first key on it will tell me the system is off when it wasn't off last time I drove it. Just for a second though, once I put it in reverse it always works fine.

 

[Doubeleive]

Tried the key on x2 reset tip tonight - no good. Darn I was really hoping it would be something simple like that.
My rear defrost has not worked since I bought the rig. When I bought it the P/S coiled wire was detached. I glued it on with the conductive glue kit available online - I thought I was getting conductivity to the grid, but I recall this winter it seemed like it was still not working. It's on my list to do some more troubleshooting. But it's never worked and remote start did when I first bought the rig. It's possible it could be the back glass, but there's a DIC message that definitely lets me know if it's not latched.



I thought I found all the remote start menus - there was the one that said I was getting an ECM abort, but I never found a menu item that said why it was aborting. I was just looking at my phone and it looks like I erased the screen shots I took, so maybe I'll try it again.

Could R/S not working have anything to do with the backup sensor system? My system is working (mostly) normally now, but I've had some troubles with it in the past. I thought the issue was with the module so I replaced that with a used one. When I realized that the module was not the problem, I went back to my original module, because with that module you get an error if it doesn't match the VIN. So no issue, but possibly some residual effects from doing that swap? And I replaced two of the original sensors with used OEMs from eBay. System works great now, but it seems overly sensitive, getting triggered from the side of my garage door opening when I back out. And sometimes when I first key on it will tell me the system is off when it wasn't off last time I drove it. Just for a second though, once I put it in reverse it always works fine.

rear defrost has nothing to do with anything, that is a open/close circuit and is only manually operated on a 10 minute timer when the key is on and the button is pushed, if you cycle the key it goes off. It is also a dumb circuit it has no idea if it is working or not, it just powers on if the circuit is broken it does not know it.
the circuit is left & right mirror and rear glass. (heater circuit), it does not self test, it does not ever get turned on by anything other than manually pressing the button.
that being said a person "could" connect a relay to key on power to trigger the defrost circuit and it could be master controlled with a toggle switch. so say in the summer it is flipped off.
pretty sure it works just like the tow button, short to ground on the bcm pin when the button is depressed. (circuit normally open)

And not to be confused with the front window "defrost hvac mode", all that does is blow air up at the glass and dehumidifies with the ac pump. small side vents also aim air at the front driver & passenger front windows near the rear view mirrors

 

[Tahoe14]

There is a rear frost repair kit that others have used and I think it’s called frost repair kit, not sure if yours is the same. Did you check the fuse for the defrost.

 

[Fless]

There is a rear frost repair kit that others have used and I think it’s called frost repair kit, not sure if yours is the same. Did you check the fuse for the defrost.

Frost Fighter is the brand.

 

[Tozan]

As @Doubeleive Said the rear defroster does not affect it.. Mine has been disconnected for years and the remote start works fine.

 

[DaveO9]

As @Doubeleive Said the rear defroster does not affect it.. Mine has been disconnected for years and the remote start works fine.

Agreed. the thread drifted a little off topic, but still useful info for those of us that have non-functional rear defrost. (I've tried the frost fighter kit or similar, I think I still have some issues. Some further troubleshooting needed)

I'm still no closer to resolving my remote start issue. Have eliminated a bunch of possibilities, but not sure where to look next. One question: Tech 2 says there is an "ECM Abort." Does that mean the ECM is aborting the sequence due to an internal check it is doing, or is it being told it needs to abort by some other module? If it was the former, it would narrow down the possibilities a lot, i.e. only things within the ECM's purview, but if it's the latter, it could be anything telling the ECM to abort the sequence.

Does anyone know if there is a diagnostic tree in the shop manuals/AllData?

 

[petethepug]

Sorry to lead astray with rear defrost….

Tech2 map may get you there. If you download it to a desktop PC you can search with a keyword by holding down the control button then the F key.

A menu will pop up to type and search out a particular word or DTC code with laser beam accuracy so every search you make counts.

Post in thread 'BCM and Tech2'
https://www.tahoeyukonforum.com/threads/bcm-and-tech2.149479/post-1893704