Howdy y'all; I'm about to info dump, but I'm at my wits-end with this right now, and I need some fresh brains and perspectives right now.
We've had a lot of cold weather lately, nothing too crazy for the midwest, but I'm sure the cold certainly isn't helping. The battery ended up dying on me two weeks ago, after replacing it, the car seemed to run just fine for a couple of days.
A couple days after replacing the battery, we had near-zero temps and while the physical parts of the car ran with no issues on my way to work, the center console was unresponsive and the steering wheel radio controls weren't working. Finished up my shift, and then had a no crank no start.
After getting the car towed home, I figured since the cold and the starter was factory, I was better off just replacing the starter and the starter relay. No dice.... No crank, no start. All electrical contacts were cleaned up and inspected while I was reassembling, all looked good. Out of frustration, I decided to replace all the fuses related to the ignition and ECM systems despite checking all of them six months prior (put a pin in that, I'm going to come back to it). Still nothing. Scanned OBD and p0633 code came up, which leads me to believe my issue is with the theft deterrent system.
Back in May last year, I had a whole sleugh of issues pertaining to vacuum leaks, lean codes, o2 voltages, and a bad turbo wastegate. I had the time and money, so I ended up replacing the turbo, the catalytic converter, valve cover, up and downstream o2 sensors, and the intake manifold that I regrettably let my partner's father install a bypass on a few years prior (I've since elected to do all of my repairs myself, using oem or upgraded aftermarket parts). The intake and exhaust systems passed a pressure test, but I was still having an intermittent limp condition. Every couple of weeks, the car would go into limp mode as I was slowing down to a stop or at idle. In August, I ended up eventually replacing both the negative battery terminal ground wire, and the ECM. I decided to replace the ECM because of an expired TSB that I wasn't notified of. The ECM was flashed to VIN and antitheft and crankshaft position relearn procedures were completed, and I haven't had issues with it until these latest couple of rounds of sub-freezing temps. I think the battery had issues caused by bad grounding, and died in the cold.
Now we're back to my current issue. The battery is good, and I still have charge. Center console seems to be booting up normally, but I still think my issue is in the BCM. Using my OBD Scanner, I can see that the ECM does appear to recognize my keys, but the theft deterrent module doesn't seem to want to disengage while I'm attempting to start the car, causing the no crank no start. That's at least, my prevailing theory, but I'm open to suggestions. I'm trying to exhaust all other options because I don't want to have to take out the steering wheel to get to the theft deterrent module. The thought of taking a deployed airbag to the face in the pursuit of fixing this car doesn't exactly spark joy. In the meantime, this morning and afternoon I will be taking advantage of the fact that it's almost 40°f outside and checking again for electrical continuity in the starter's systems to see if there's something I missed. I will also be checking the fuses in the BCM's systems as it's my understanding the VATS systems are controlled by both the ECM and BCM.
I'm just reaching out because maybe I've overlooked something obvious, or someone who has had a similar experience can lend a nugget of wisdom. Also, I'm documenting this just in case anyone in the future has the same issues I have. This has me nearly frustrated to tears; but I fucking love this turd, and I just can't seem to let it go.
Thanks,
-Kraxistor
We've had a lot of cold weather lately, nothing too crazy for the midwest, but I'm sure the cold certainly isn't helping. The battery ended up dying on me two weeks ago, after replacing it, the car seemed to run just fine for a couple of days.
A couple days after replacing the battery, we had near-zero temps and while the physical parts of the car ran with no issues on my way to work, the center console was unresponsive and the steering wheel radio controls weren't working. Finished up my shift, and then had a no crank no start.
After getting the car towed home, I figured since the cold and the starter was factory, I was better off just replacing the starter and the starter relay. No dice.... No crank, no start. All electrical contacts were cleaned up and inspected while I was reassembling, all looked good. Out of frustration, I decided to replace all the fuses related to the ignition and ECM systems despite checking all of them six months prior (put a pin in that, I'm going to come back to it). Still nothing. Scanned OBD and p0633 code came up, which leads me to believe my issue is with the theft deterrent system.
Back in May last year, I had a whole sleugh of issues pertaining to vacuum leaks, lean codes, o2 voltages, and a bad turbo wastegate. I had the time and money, so I ended up replacing the turbo, the catalytic converter, valve cover, up and downstream o2 sensors, and the intake manifold that I regrettably let my partner's father install a bypass on a few years prior (I've since elected to do all of my repairs myself, using oem or upgraded aftermarket parts). The intake and exhaust systems passed a pressure test, but I was still having an intermittent limp condition. Every couple of weeks, the car would go into limp mode as I was slowing down to a stop or at idle. In August, I ended up eventually replacing both the negative battery terminal ground wire, and the ECM. I decided to replace the ECM because of an expired TSB that I wasn't notified of. The ECM was flashed to VIN and antitheft and crankshaft position relearn procedures were completed, and I haven't had issues with it until these latest couple of rounds of sub-freezing temps. I think the battery had issues caused by bad grounding, and died in the cold.
Now we're back to my current issue. The battery is good, and I still have charge. Center console seems to be booting up normally, but I still think my issue is in the BCM. Using my OBD Scanner, I can see that the ECM does appear to recognize my keys, but the theft deterrent module doesn't seem to want to disengage while I'm attempting to start the car, causing the no crank no start. That's at least, my prevailing theory, but I'm open to suggestions. I'm trying to exhaust all other options because I don't want to have to take out the steering wheel to get to the theft deterrent module. The thought of taking a deployed airbag to the face in the pursuit of fixing this car doesn't exactly spark joy. In the meantime, this morning and afternoon I will be taking advantage of the fact that it's almost 40°f outside and checking again for electrical continuity in the starter's systems to see if there's something I missed. I will also be checking the fuses in the BCM's systems as it's my understanding the VATS systems are controlled by both the ECM and BCM.
I'm just reaching out because maybe I've overlooked something obvious, or someone who has had a similar experience can lend a nugget of wisdom. Also, I'm documenting this just in case anyone in the future has the same issues I have. This has me nearly frustrated to tears; but I fucking love this turd, and I just can't seem to let it go.
Thanks,
-Kraxistor
