arcman
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- Genesis Model Type
- 2G Genesis Sedan (2015-2016)
I told part of this story in a previous post about people having issues with instrument cluster warnings but there ended up being much more...
(Warning... Very long story)
I purchased my 2015 Ultimate from a IAAI auto salvage auction in Nov. 2018, listed as flood car. Before bidding I called some towing companies near Plano, TX where the car was up for auction and got lucky and found where and who worked on the car before being totaled.
The car was in a parking lot in Galveston, TX during Hurricane Harvey (Aug. '17). The owner came back from a cruise to find wet carpet and a water mark halfway up seat bottoms. He took the car to the dealer in Waco, Tx. and they spent around $14,000 in interior repairs (the dealer wouldn't tell me exactly what they were). The car had no error codes at the time.
After the repairs, the owners drove the car for full year and in Oct. '18 it started throwing multiple fault codes. The dealer could not track down the problem and sent it to a electrical speciality shop in Dallas. They drove the car for a week with no fault codes and then it finally replicated what the owners saw. Pre-safe belt tensioner, Lane Keep Assist, Blind spot indicator, TPMS etc.
The electrical shop dug into it and in the end all they could come up with was a 'complete loss of communication on CAN bus C'. After ringing up $760 in labor and no fix, the insurance company decided they spent enough on it and totaled the car. Both the dealer and the second shop noted the car got wet from an open sunroof (which was the one reason for me bidding on the car) but I found later in a phone call after tracking down the previous owner, that was BS. The electrical shop noted there was no sign of salt water corrosion. I've seen none.
With only half a dozen pics in the auction listing, I took a leap of faith and decided to bid on the car. After about 45 seconds of going against only one other bidder in Georgia, I got the car for $10,500. All totaled, with auctions fees, transport to WI, taxes, license etc, I have $12,500 in it. 38K miles and near mint condition. The car arrived in Wisconsin just after Thanksgiving and the only thing I did was buy a battery and re-attach a bunch of plastic floor and dash panels they left in the trunk.
I drove the car for five months with zero fault codes until sometime around April or May. For all that time I thought I'd gotten away with it but as soon as it hit 65 degrees outside, the dash started dinging and up came the same trouble codes the original owners complained of. As the outside temp rose, the trouble codes eventually came every time I drove the car. The car never went into the 'limp mode' but the dash was a mess and the turn indicators now wouldn't work so I really couldn't drive it that way.
Knowing taking it back to a dealer would probably end up being a time & money waster, I started with purchasing one of the knock off Hyundai scan tools. It's a nice tool but really didn't help with diagnosing this problem. We knew we had a issue on CAN bus C because of so many failed modules were on it but was it a module or a corroded wire, bad connector??
A good friend who designs embedded controls offered to help and we put a oscilloscope on the C bus. The CAN bus C is for the chassis and includes 35 modules on this car. Lane Keep Assist, Tire pressure monitor, seat belt, cruise control... 35 of them. Where do you start? The bus is actually just two twisted wires that run from the front bumper to the roof, throughout the entire car all the way to the back bumper. The modules send and receive data from other modules with just a voltage change representing twin opposing square waves. The scope did see the problem. The signal had sporadic moments of complete (but symmetrical) gibberish.
Here's a good signal with opposing CAN Hi and CAN lo.
Here's ours. (just Can Hi). (We spent quite a bit of time trying to capture this frame with the scope trigger because it goes by in milliseconds.)
My friend felt the corrupted signal was due to a fault in a module, not a corroded wire or connection because of what he saw in the symmetry of the signal. (ended up being a good call!)
With that in mind and because of some repeatable conditions (I won't go into), I felt it could be the Smart Cruise Control module behind the grille. If I disconnected the module, all I got was SCC on the dash. I drove it for a week with no other errors, so I bought a good condition used one (local dealer mechanic said it often was the problem) but unfortunately it didn't help. (My friend warned me this approach probably wouldn't work... I can be stubborn.)
Now the errors were coming up more often, even with the SCC and the LKAS modules disconnected.
I spent hours watching CAN bus videos on Youtube, digging on Google, calling dealers and a few shops I could get any info from and in the end pretty much everyone said to continue disconnecting modules and see what happens. Even the dealers approach it this way as they have no tools to diagnose this kind of bus issue!
Trouble is many of the modules are up in the dash and next to impossible to get to. Four of them were accessible but none of them were the culprit.
All this time I had it in the back of my head it most likely had to be something that got wet in the flood and the Electronic Parking Brake was a possibility. It was pretty high up, above the rear diff but who knows... maybe the water got that high up. Maybe wheel speed sensors (TPMS). Both were modules that had errors in the scans.
The EPB connector was nearly impossible to disconnect due to a tight space but luckily there was a sister connector in the right rear wheel well. After disconnecting it, I drove it for two weeks and had no errors. I found a used one for $75 on Ebay and was about to buy it when my friend said why not try replacing the transceiver chip first? I checked resistance values on the modules CAN Hi and Lo wires to ground and they were quite a ways off compared to other modules so felt there was a possibility we were on to something.
Here's the module. At first I didn't think I could get it out because it is seriously wedged between the diff and trunk/rear seat floor. But after removing the rear wheels, rotors, some clips and a heat shield, I managed to get it out. What you're looking at is basically a motor that turns a jack screw, pulling both cables together, that apply drum brake shoes inside the rear rotors. To the right of the motor is the control board.
Here's the control board. Every one of the modules in this car has a IC chip called a transceiver that does the communicating with the other modules. The square chip in the middle of this shot is that chip. Extremely common, I bought one from Digi-key for $1.46, put everything back together and the car is fixed. That bad chip corrupted the entire chassis bus.
That was three months ago and since then I've had no dash warnings. I just recently scanned the system and found zero fault codes.
To my surprise, there wasn't any water, condensation or corrosion in the EPB. Just a failed chip that had nothing to do with the flood issue.
Tough loss for the insurance company. After spending a ton of money on repairing the car, they bailed after spending maybe another grand between the two shops. I'm sure the electrical shop would have found this with enough time but who knows... They'd been in the trunk, pulled floor and toe kick panels out and were already heading in the wrong direction because they started tearing the dash apart thinking it was somewhere in there.
With maybe 20-30 hrs actually working on this thing, I got lucky. A great car with a new interior for less than half of what they sell for. What a joy to drive.
(I do have that driveshaft noise thing and I'm working on that. I thought it was the rubber couplers but some people I've talked to in the driveline biz say it's the U-joint. I am NOT buying a $1,000 driveshaft. Will report when we get it fixed.)
(Warning... Very long story)
I purchased my 2015 Ultimate from a IAAI auto salvage auction in Nov. 2018, listed as flood car. Before bidding I called some towing companies near Plano, TX where the car was up for auction and got lucky and found where and who worked on the car before being totaled.
The car was in a parking lot in Galveston, TX during Hurricane Harvey (Aug. '17). The owner came back from a cruise to find wet carpet and a water mark halfway up seat bottoms. He took the car to the dealer in Waco, Tx. and they spent around $14,000 in interior repairs (the dealer wouldn't tell me exactly what they were). The car had no error codes at the time.
After the repairs, the owners drove the car for full year and in Oct. '18 it started throwing multiple fault codes. The dealer could not track down the problem and sent it to a electrical speciality shop in Dallas. They drove the car for a week with no fault codes and then it finally replicated what the owners saw. Pre-safe belt tensioner, Lane Keep Assist, Blind spot indicator, TPMS etc.
The electrical shop dug into it and in the end all they could come up with was a 'complete loss of communication on CAN bus C'. After ringing up $760 in labor and no fix, the insurance company decided they spent enough on it and totaled the car. Both the dealer and the second shop noted the car got wet from an open sunroof (which was the one reason for me bidding on the car) but I found later in a phone call after tracking down the previous owner, that was BS. The electrical shop noted there was no sign of salt water corrosion. I've seen none.
With only half a dozen pics in the auction listing, I took a leap of faith and decided to bid on the car. After about 45 seconds of going against only one other bidder in Georgia, I got the car for $10,500. All totaled, with auctions fees, transport to WI, taxes, license etc, I have $12,500 in it. 38K miles and near mint condition. The car arrived in Wisconsin just after Thanksgiving and the only thing I did was buy a battery and re-attach a bunch of plastic floor and dash panels they left in the trunk.
I drove the car for five months with zero fault codes until sometime around April or May. For all that time I thought I'd gotten away with it but as soon as it hit 65 degrees outside, the dash started dinging and up came the same trouble codes the original owners complained of. As the outside temp rose, the trouble codes eventually came every time I drove the car. The car never went into the 'limp mode' but the dash was a mess and the turn indicators now wouldn't work so I really couldn't drive it that way.
Knowing taking it back to a dealer would probably end up being a time & money waster, I started with purchasing one of the knock off Hyundai scan tools. It's a nice tool but really didn't help with diagnosing this problem. We knew we had a issue on CAN bus C because of so many failed modules were on it but was it a module or a corroded wire, bad connector??
A good friend who designs embedded controls offered to help and we put a oscilloscope on the C bus. The CAN bus C is for the chassis and includes 35 modules on this car. Lane Keep Assist, Tire pressure monitor, seat belt, cruise control... 35 of them. Where do you start? The bus is actually just two twisted wires that run from the front bumper to the roof, throughout the entire car all the way to the back bumper. The modules send and receive data from other modules with just a voltage change representing twin opposing square waves. The scope did see the problem. The signal had sporadic moments of complete (but symmetrical) gibberish.
Here's a good signal with opposing CAN Hi and CAN lo.
Here's ours. (just Can Hi). (We spent quite a bit of time trying to capture this frame with the scope trigger because it goes by in milliseconds.)
My friend felt the corrupted signal was due to a fault in a module, not a corroded wire or connection because of what he saw in the symmetry of the signal. (ended up being a good call!)
With that in mind and because of some repeatable conditions (I won't go into), I felt it could be the Smart Cruise Control module behind the grille. If I disconnected the module, all I got was SCC on the dash. I drove it for a week with no other errors, so I bought a good condition used one (local dealer mechanic said it often was the problem) but unfortunately it didn't help. (My friend warned me this approach probably wouldn't work... I can be stubborn.)
Now the errors were coming up more often, even with the SCC and the LKAS modules disconnected.
I spent hours watching CAN bus videos on Youtube, digging on Google, calling dealers and a few shops I could get any info from and in the end pretty much everyone said to continue disconnecting modules and see what happens. Even the dealers approach it this way as they have no tools to diagnose this kind of bus issue!
Trouble is many of the modules are up in the dash and next to impossible to get to. Four of them were accessible but none of them were the culprit.
All this time I had it in the back of my head it most likely had to be something that got wet in the flood and the Electronic Parking Brake was a possibility. It was pretty high up, above the rear diff but who knows... maybe the water got that high up. Maybe wheel speed sensors (TPMS). Both were modules that had errors in the scans.
The EPB connector was nearly impossible to disconnect due to a tight space but luckily there was a sister connector in the right rear wheel well. After disconnecting it, I drove it for two weeks and had no errors. I found a used one for $75 on Ebay and was about to buy it when my friend said why not try replacing the transceiver chip first? I checked resistance values on the modules CAN Hi and Lo wires to ground and they were quite a ways off compared to other modules so felt there was a possibility we were on to something.
Here's the module. At first I didn't think I could get it out because it is seriously wedged between the diff and trunk/rear seat floor. But after removing the rear wheels, rotors, some clips and a heat shield, I managed to get it out. What you're looking at is basically a motor that turns a jack screw, pulling both cables together, that apply drum brake shoes inside the rear rotors. To the right of the motor is the control board.
Here's the control board. Every one of the modules in this car has a IC chip called a transceiver that does the communicating with the other modules. The square chip in the middle of this shot is that chip. Extremely common, I bought one from Digi-key for $1.46, put everything back together and the car is fixed. That bad chip corrupted the entire chassis bus.
That was three months ago and since then I've had no dash warnings. I just recently scanned the system and found zero fault codes.
To my surprise, there wasn't any water, condensation or corrosion in the EPB. Just a failed chip that had nothing to do with the flood issue.
Tough loss for the insurance company. After spending a ton of money on repairing the car, they bailed after spending maybe another grand between the two shops. I'm sure the electrical shop would have found this with enough time but who knows... They'd been in the trunk, pulled floor and toe kick panels out and were already heading in the wrong direction because they started tearing the dash apart thinking it was somewhere in there.
With maybe 20-30 hrs actually working on this thing, I got lucky. A great car with a new interior for less than half of what they sell for. What a joy to drive.
(I do have that driveshaft noise thing and I'm working on that. I thought it was the rubber couplers but some people I've talked to in the driveline biz say it's the U-joint. I am NOT buying a $1,000 driveshaft. Will report when we get it fixed.)
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