[FadiM]

Hey Community,
I was hoping this day wouldn't come since the car is maintained regularly and barely driven outside the track. Oh was I wrong, on the final round right before cool off, the engine cut the power on full throttle. I cooled off and drove into the pit stop

1. I let it cool off for a good amount of time (I thought I just pushed it too hard)
2. Turned on the ignition and went on home
3. Check engine came on mid-way (but car was operating normally and boost engaging)
4. Cleared the code, Didn't drive it for a few days and then took it for a quick spin on the street I live in
5. Started vibrating then stalled (at this point, I was like ok not an overboost problem I was facing earlier)
6. Had it towed to my mechanic
7. He hooked it up and this is what we got (I'm baffled!!) - Car running as smooth as a whistle, no codes, and boom 20 fault codes
8. Worth mentioning the car has Zero boost now
9. Here are the codes, I hope one of you could chime in as it may be one culprit causing all this to flare up

I remember a decade ago when had an X5 and when the battery would be shot, it would be throwing all sorts of codes (not sure if Caddy's are as weird as that)

Or maybe I blew an Intercooler hose?

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[tta1456]

Looks like a possible bad battery or a wiring harness/ground issue with all those happening at once.

What year is your car? Some of the early 2016s had an issue where the engine harness could chafe near the front passenger side corner of the engine, but there was a TSB for that to move the harness and attach some heavy plastic loom over it as a rub block.

 

[FadiM]

Looks like a possible bad battery or a wiring harness/ground issue with all those happening at once.

What year is your car? Some of the early 2016s had an issue where the engine harness could chafe near the front passenger side corner of the engine, but there was a TSB for that to move the harness and attach some heavy plastic loom over it as a rub block.

Thanks, I'll check the battery today and the ground wiring harness

It's a late model 2016 but worth checking the engine harness. Thanks for the input!

 

[tta1456]

Actually, there's 2 bulletins now for the harness chafing... the original one for 2016s where it could contact the valve cover bolt and rub through, and a newer one where it can hit the alternator pulley.

Both TSBs:

https://static.nhtsa.gov/odi/tsbs/2015/SB-10089883-2280.pdf

https://static.nhtsa.gov/odi/tsbs/2017/MC-10130536-9999.pdf

 

[Hib_Halverson]

I kind of agree with some of the other posts here.

I think you have a major engine controls wiring problem somewhere. Look for the chafing problem discussed on those TSBs. Also look for a wiring harness that's been melted or burned by the exhaust.

 

[FadiM]

Thanks guys for the input and sorry for not getting back sooner. We changed the battery as a precaution since hasn't been changed since bought. No leaks either.

I've passed on the info to my mechanic so hopefully this will pin down the problem.

I plan to go over there tomorrow once get off work.

 

[tta1456]

Hib's suggestion is a good one too, heat damage to one of the harnesses near the turbos and converters is something I thought about but forgot to mention in my original post.

There's a couple of wire harnesses down near the bellhousing next to the catalytic converters that feed the O2 sensors, and they could be damaged from prolonged heat; the harnesses do have thermal wrapping on them to protect them from ambient heat coming from the turbos and catalytic converters but they might possibly be damaged; saw that happen on a car that had poor fitting aftermarket downpipes installed, the aftermarket downpipes were far too close to the wire harness on the passenger side and the heat ended up cooking the harness after a while.

It may also be something as simple as one of the O2 sensors has completely failed internally and the heater and signal circuits are now shorted together, which would cause all kinds of weird issues...

 

[FadiM]

Hib's suggestion is a good one too, heat damage to one of the harnesses near the turbos and converters is something I thought about but forgot to mention in my original post.

There's a couple of wire harnesses down near the bellhousing next to the catalytic converters that feed the O2 sensors, and they could be damaged from prolonged heat; the harnesses do have thermal wrapping on them to protect them from ambient heat coming from the turbos and catalytic converters but they might possibly be damaged; saw that happen on a car that had poor fitting aftermarket downpipes installed, the aftermarket downpipes were far too close to the wire harness on the passenger side and the heat ended up cooking the harness after a while.

It may also be something as simple as one of the O2 sensors has completely failed internally and the heater and signal circuits are now shorted together, which would cause all kinds of weird issues...

That is a possibility since the codes did indicate a failed o2 sensor or low circuit. Not to mention I had the RP Downpipes installed last year. It could be they didn't protect the wires like they should.

Thanks guys!

 

[FadiM]

Hey fellow Supporters,
Thought would give another update. All wiring was checked and came back clean.

They cleaned up all the sensors and connections, now going to be putting back everything together to see if it fixes the problem.

Nevertheless, I'm going ahead and changing most of the sensors, the O2's, wastegate Solenoids, MAF sensor, and a few others. I figured while the car is there just replace everything since I push the car real hard. Also, I sometimes I do mix some boostane (another reason why the O2 may have failed)

Not the most cost efficient way to do things but you never know what's about to die on me so better safe than sorry.

Shipment should be coming in by 31st so will post an update.

It's worth mentioning I went with an aftermarket battery when I replaced it since OEM was a unnecessarily overpriced. I checked some posts and made sure it had the same specs. Could it be that again these cars don't like this?

Again going back to my Bimmer. I installed non-OEM Battery caused a whole load of electric issues back in the day. Hope I don't pay that price again for trying to save a few $$$

 

[FadiM]

Update: The sensors were changed and the car still has no boost. At this point all I can say is I'm baffled.

Assuming it was a leak, I'd be getting some boost but in my case it's a Zero. As if the turbo isn't engaging at all. Could it be a fuse 🙄

 

[Glennhl]

Could be the boost sensor or gauge is broken? Does it feel like it's coming up to boost when you go full throttle?

 

[FadiM]

Could be the boost sensor or gauge is broken? Does it feel like it's coming up to boost when you go full throttle?

I changed the boost sensor while I was at it. Nope no boost, just a regular boring acceleration and no thrill.

Turned out the Fuses are intact as well. I'm headed there today again to stay on top of the mechanics head (it's time to be one of those guys)

 

[FadiM]

I changed the boost sensor while I was at it. Nope no boost, just a regular boring acceleration and no thrill.

Turned out the Fuses are intact as well. I'm headed there today again to stay on top of the mechanics head (it's time to be one of those guys)

I spent a few hours there and they're questioning the actuators and that it could be the cause of the problem. I'm doing some research on this now, and though it may cause loss of power as if you had bad gas, there's no linking to not having boost. I'll look more into this.

 

[FadiM]

Another update: actuators came back clean according to the mechanic. I've decided to cut my losses with them, towing it out tomorrow and taking it to who they refer to as "The guy" to get it done.

I have to say I've never seen such a stubborn problem. I still have 18 codes that won't clear either.

I'm not an expert myself but its definitely an electric issue but they insisted it came back clear.

Let's see if this guy has better luck. Safe to say I'm missing the next track day as well on the 10th. A bummer though, it was on the GP track (the bigger one)

 

[FadiM]

Final Update (I hope):
Just got word from the new guy and he's fixed the problem (I hope🤞), It was the computer. Luckily, this is some Electrical guru and fixed it. The fix was mainly two things

• Changed some burnt out resistors
• and the IC?

I'm not really that savvy to understand the second one but I'll know more once I pick up the car. The question is now, how did they get fried to begin with?

 

[tta1456]

Good news.

If the wiring all checked out (and it sounded like it did) then a fault in the ECM was the next place to look with that many errors happening at once.

95% of the time multiple faults like you were seeing are usually related to wiring harness issues or a bad sensor taking out an entire +5V or +12V reference line or ground that is shared with multiple sensors, that's why they're always the first thing to check.

An ECM failure is much more uncommon in my experience, but it does happen. Just last weekend I was helping a friend with a Ford F-250 that ended up having multiple failed injector drivers in the ECM. Truck was driving fine the previous weekend on a dump run, then wouldn't start the following weekend... wiring and injectors tested OK but there was no injector signal on the scope coming from the ECM. Picked up a rebuilt ECM and fired right up.

Could have just been a freak occurrence some components failed in your ECM, doesn't necessarily mean they failed because of a wiring or sensor issue.

 

[FadiM]

Good news.

If the wiring all checked out (and it sounded like it did) then a fault in the ECM was the next place to look with that many errors happening at once.

95% of the time multiple faults like you were seeing are usually related to wiring harness issues or a bad sensor taking out an entire +5V or +12V reference line or ground that is shared with multiple sensors, that's why they're always the first thing to check.

An ECM failure is much more uncommon in my experience, but it does happen. Just last weekend I was helping a friend with a Ford F-250 that ended up having multiple failed injector drivers in the ECM. Truck was driving fine the previous weekend on a dump run, then wouldn't start the following weekend... wiring and injectors tested OK but there was no injector signal on the scope coming from the ECM. Picked up a rebuilt ECM and fired right up.

Could have just been a freak occurrence some components failed in your ECM, doesn't necessarily mean they failed because of a wiring or sensor issue.

Thanks for this. Also happy to know that in rare occasions something like this could happen.

I went by the mechanic yesterday and took the caddy for a quick spin and runs like new. The upside to all this is that the car has been checked bumper to bumper, cleaned connectors, and all the major sensors were changed so I'm in the clear for a while.

I contacted Scott from tapout and will be ordering a remote tune

I'm not going to take risks since the only thing I did before this was adjust the custom tune I did. Maybe, just maybe, that was the reason.

The guy also told me could have been the battery which I already changed that was acting up.

I couldn't be certain but what counts now is that I'm finally getting the car back!

Thanks for all the inputs!