Remote Start Troubleshooting - SOLVED

[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

 

[DaveO9]

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

Sounds good, I'll do some sleuthing. Great link to the pathing document, thanks!

 

[Tozan]

I want to derail the thread a little bit but, it's still related to the topic... lol Where is the remote antenna located on a 2011 Tahoe?

 

[mikez71]

Number 1 is the Remote Control Coor Lock Receiver. (RCDLR?)
One of the cables that plugs into is (to?) antenna.

 

[Doubeleive]

ya it's in the rear drivers area behind the panel, might be as pictured above or more forward near the wheel well I have seen pictures of it, definetely rear drivers side though
it could vary possibly depending on the year and if it is swb/lwb. or it could be there on all of them, hard to say from the pictures I have seen
pretty sure it requires programming as well if replaced.

 

[Tozan]

Thanks that gives me a great place to start looking. I insulated that whole area with a foil lined insulation, I wonder if that is why my reception went way down..

 

[DaveO9]

I'm getting back to working on this after a long hiatus - winter's here.

I've checked/done pretty much everything listed in this thread. Some of them multiple times. Recently went back to the very basics: made sure Remote Start is turned on in DIC - check. Made sure I have AP3 RPO - check. No CEL. No funky electrical gremlins of any kind. The only codes I get from all Tech 2 diagnostics: 1) lost connection with radio (aftermarket) and 2) B2555, which is covered from this TSB: https://static.nhtsa.gov/odi/tsbs/2013/SB-10051905-4497.pdf

The main things I know:
1. Both remotes will initiate the sequence. Parking lights flash, fuel pump primes for a second, a relay clicks under the hood.
2. Tech2 tells me there is an "ECM Crank Abort" on the remote start screen. I have had zero luck in finding any cause of that abort.

I have not found a way to actually use the Tech 2 to perform the remote start. It allows me to test all the buttons on the remotes, and all buttons including RS register a push. So I'm convinced it's not the remotes. Tech2 has also allowed me to rule out door locks, rear lift gate and hatch, and hood ajar. Everything is testing properly.

What could cause the ECM crank abort method without a CEL or other codes?

@swathdiver (or anyone else) does the AllDataDIY have a diagnostic procedure? I wouldn't mind paying for the short subscription if there is one available. I did purchase the $10 ebay service module that comes in like 30 different files. It's a good copy and will be useful eventually, but I can't find a single thing about remote start in there. There doesn't seem to be a master index that covers all the different files. (or really any index at all)

 

[mikez71]

Here's a video with some info..

Sounds like this guy had an engine code that prevented it from starting, but he does go over some requirements for remote start to work..

Also seen a thread about a bad hood latch wire which prevented remote start.
Looking at the diagram below, it appears there is a switch for hood closed as well as ajar.
I'm guessing if the 'closed' switch isn't active, no remote start and no hood ajar message.

 

[Doubeleive]

I don't know but sub'd to find out
I read there could be a ground issue that could cause a ECM abort
I think a little more probing with the tech2 might point you in the right direction
compare data from before start attempt to after start attempt, you will want to attach a external 12v power adapter so it doesn't reboot while testing.

 

[DaveO9]

Here's a video with some info..

Sounds like this guy had an engine code that prevented it from starting, but he does go over some requirements for remote start to work..

Also seen a thread about a bad hood latch wire which prevented remote start.
Looking at the diagram below, it appears there is a switch for hood closed as well as ajar.
I'm guessing if the 'closed' switch isn't active, no remote start and no hood ajar message.

View attachment 443003

Thanks, the video was helpful. Yes, his solution ended up being pretty easy since he had a CEL, but it confirmed some things for me - in particular, with a RS request, BCM first does its set of tests, then if all pass, it sends the request to the ECM which also does a set of tests. Since I'm getting an "ECM - Crank abort" error, I'm pretty sure BCM tests pass, but something fails at the ECM. Did another ECM diagnostic tonight - zero codes.

Regarding the hood switches. The remote start screen on the Tech2 makes it look like there are three: hood ajar, hood open, and hood closed. (But maybe open and closed are just one switch) In any case, they are all behaving properly according to the Tech 2. They change status as expected when opening and closing the hood. Plus, I think those tests are in the BCM, and I think I'm getting past that. But all helpful, thanks.

I don't know but sub'd to find out
I read there could be a ground issue that could cause a ECM abort
I think a little more probing with the tech2 might point you in the right direction
compare data from before start attempt to after start attempt, you will want to attach a external 12v power adapter so it doesn't reboot while testing.

Yeah a ground issue is about all I can come up with now too with the symptom of a crank abort but with no codes or CEL. I did a little playing around with the charging info screen before and after a regular start tonight. Is that what you're suggesting? I didn't see anything abnormal either before or after an engine start. I did recently replace the positive cable from battery to starter (was hoping that would solve this problem - no luck). Perhaps I should replace the negative cable too. But like I mentioned, no noticeable electrical issues anywhere else.

 

[Doubeleive]

Thanks, the video was helpful. Yes, his solution ended up being pretty easy since he had a CEL, but it confirmed some things for me - in particular, with a RS request, BCM first does its set of tests, then if all pass, it sends the request to the ECM which also does a set of tests. Since I'm getting an "ECM - Crank abort" error, I'm pretty sure BCM tests pass, but something fails at the ECM. Did another ECM diagnostic tonight - zero codes.

Regarding the hood switches. The remote start screen on the Tech2 makes it look like there are three: hood ajar, hood open, and hood closed. (But maybe open and closed are just one switch) In any case, they are all behaving properly according to the Tech 2. They change status as expected when opening and closing the hood. Plus, I think those tests are in the BCM, and I think I'm getting past that. But all helpful, thanks.



Yeah a ground issue is about all I can come up with now too with the symptom of a crank abort but with no codes or CEL. I did a little playing around with the charging info screen before and after a regular start tonight. Is that what you're suggesting? I didn't see anything abnormal either before or after an engine start. I did recently replace the positive cable from battery to starter (was hoping that would solve this problem - no luck). Perhaps I should replace the negative cable too. But like I mentioned, no noticeable electrical issues anywhere else.

no I would probably be looking at security data, ignition status, bcm. I don't know if there is a remote start section in there or not.
does it work if you have it running, press the remote start button, then remove the key? if so see if after it times out the 1st time, see if will remote start on the 2nd time
(2 remote starts are allowed without a key cycle)
I would also be looking at brake pedal status & accelerator pedal
maybe something below will help?