AWD and various other malfunctions

[Mk7noob85]

Looking for a bit of guidance or theories before I spend more money just parts swapping.


I have a 2016 R DSG DCC @ 70k miles, Unitronic stage 1 ECU/TCU

I bought the car to fast because I loved it and wanted it. I SHOULD have checked things out more closely before buying ... but I didn't. as I've worked on it and done maintenance I have found things that I don't really like and it leads me to believe it was modded and probably abused. Was a lease that was returned and sold to me as a CPO for way too much money.

1. It was debadged and had a "Quatro" sticker over the windshield along with stickers down both rockers
2. has a vacuum tap and vacuum line run to the interior fuse panel (drivers kick panel) that was folded over and ziptied instead of properly capped off.
3. mounting points for the factory intake airbox were broken
4. resonator was removed and poorly rewelded into place
5. exhaust flap motor connectors modified/broken
6. expensive aftermarket sparkplugs

I bought the car with 38k miles, had ECU/TCU tune flashed at a shop at 40k miles. A soon as I drove 3 miles from the shop a coil connector came loose and threw a ton of codes. snapped it back in place and drove fine for a few thousand miles.

Around 44k miles I got a rough idle, hesitation under load randomly and lots of codes. I pulled the plugs and found excessive wear on the ground strap over the electrode. I took the plugs to a parts store and was quoted $275 for a set of four plugs. Went to the dealer and got a set of factory plugs and factory coils. Installed and all issues resolved.

At 62k miles I started hearing clunking from the front passenger side when I used Launch Control. As I don't often use LC I thought maybe it was just that spot of the road. I noticed under hard acceleration I would occasionally traction control flash briefly. over the next thousand or so miles I noticed TCS light up more frequently.

At 64k miles I found AWD was no longer functional and the clunking (now severe) was wheel hop. I originally thought it was a broken axle it was so violent. I changed the haldex fluid and pump three times. First was a bad pump, second didn't sound correct, third finally worked correctly and passed the learn function with similar results to good units I had seen online. This did not resolve the AWD issue.

I then bought a used rear differential from a wrecked 2016 R with a claimed 17k miles and swapped the entire rear diff, Haldex controller, swapped the functional Haldex pump from the original diff and ... no AWD.

looking at the graphs I ran through VCDS it looks like everything is normal but after .25 seconds the PMW signal to the Haldex controller spikes to 85% then goes to 0%

That brings me to this month at 70k miles. I had to drive to south florida (600ish miles round trip). On my drive back I was cruising at 80mph and the cruise kicked off, and dash board lit up with error codes. Everything from ABS and airbags to TPMS and adaptive headlights. By the time I got to a place I could pull over everything but cruise control had returned to normal. I power cycled the car and cruise control returned. a few times I have had this issue at startup now with everything but cruise going away, then after a power cycle cruise returns.

I have attached two logs I ran a few thousand miles apart ... any experts that can point me towards any ideas? Funds are tight so I don't want to keep hurling money at things. I'm currently suspecting maybe the right rear wheel speed sensor is flaky but I'd hate to dump $150 on a new sensor for no reason. When capture data from all four wheel speed sensors they all read the same in a straight line and vary slightly when cornering. maybe intermittent failure? Is there a common wiring issue or connector issue on '16 golf R's I didn't know about. Any help would be appreciated.

 

[ShagginGSW]

Do you still get ridiculous wheel hop in your current situation? Can you put the car up on jack stands and run it to see if the DS spins? Wondering if there is possibly something wrong with the bevel box in the front that spins the DS.

 

[Mk7noob85]

Do you still get ridiculous wheel hop in your current situation? Can you put the car up on jack stands and run it to see if the DS spins? Wondering if there is possibly something wrong with the bevel box in the front that spins the DS.

lots of wheel hop when I disable TCS, just traction control and torque steer when I don't. I've had the car up on my quickjacks and everything spins with no strange noises. I have NOT been able been able to do the test where you lift the front end and leave the rear on the ground to see if the driveshaft spins under load.

I'm more interested in why the PWM signal to the haldex controller goes from 85% to 0% while the front wheels are still slipping (according to VCDS).

 

[JerseyDrew77]

Looking for a bit of guidance or theories before I spend more money just parts swapping.


I have a 2016 R DSG DCC @ 70k miles, Unitronic stage 1 ECU/TCU

I bought the car to fast because I loved it and wanted it. I SHOULD have checked things out more closely before buying ... but I didn't. as I've worked on it and done maintenance I have found things that I don't really like and it leads me to believe it was modded and probably abused. Was a lease that was returned and sold to me as a CPO for way too much money.

1. It was debadged and had a "Quatro" sticker over the windshield along with stickers down both rockers
2. has a vacuum tap and vacuum line run to the interior fuse panel (drivers kick panel) that was folded over and ziptied instead of properly capped off.
3. mounting points for the factory intake airbox were broken
4. resonator was removed and poorly rewelded into place
5. exhaust flap motor connectors modified/broken
6. expensive aftermarket sparkplugs

I bought the car with 38k miles, had ECU/TCU tune flashed at a shop at 40k miles. A soon as I drove 3 miles from the shop a coil connector came loose and threw a ton of codes. snapped it back in place and drove fine for a few thousand miles.

Around 44k miles I got a rough idle, hesitation under load randomly and lots of codes. I pulled the plugs and found excessive wear on the ground strap over the electrode. I took the plugs to a parts store and was quoted $275 for a set of four plugs. Went to the dealer and got a set of factory plugs and factory coils. Installed and all issues resolved.

At 62k miles I started hearing clunking from the front passenger side when I used Launch Control. As I don't often use LC I thought maybe it was just that spot of the road. I noticed under hard acceleration I would occasionally traction control flash briefly. over the next thousand or so miles I noticed TCS light up more frequently.

At 64k miles I found AWD was no longer functional and the clunking (now severe) was wheel hop. I originally thought it was a broken axle it was so violent. I changed the haldex fluid and pump three times. First was a bad pump, second didn't sound correct, third finally worked correctly and passed the learn function with similar results to good units I had seen online. This did not resolve the AWD issue.

I then bought a used rear differential from a wrecked 2016 R with a claimed 17k miles and swapped the entire rear diff, Haldex controller, swapped the functional Haldex pump from the original diff and ... no AWD.

looking at the graphs I ran through VCDS it looks like everything is normal but after .25 seconds the PMW signal to the Haldex controller spikes to 85% then goes to 0%

That brings me to this month at 70k miles. I had to drive to south florida (600ish miles round trip). On my drive back I was cruising at 80mph and the cruise kicked off, and dash board lit up with error codes. Everything from ABS and airbags to TPMS and adaptive headlights. By the time I got to a place I could pull over everything but cruise control had returned to normal. I power cycled the car and cruise control returned. a few times I have had this issue at startup now with everything but cruise going away, then after a power cycle cruise returns.

I have attached two logs I ran a few thousand miles apart ... any experts that can point me towards any ideas? Funds are tight so I don't want to keep hurling money at things. I'm currently suspecting maybe the right rear wheel speed sensor is flaky but I'd hate to dump $150 on a new sensor for no reason. When capture data from all four wheel speed sensors they all read the same in a straight line and vary slightly when cornering. maybe intermittent failure? Is there a common wiring issue or connector issue on '16 golf R's I didn't know about. Any help would be appreciated.

So the original owner rmoved all of the R badges and put Quattro stickers on it? Quattro is Audi so if I were you, I would remove those stickers so that you don't look like a d-bag.

 

[Mk7noob85]

So the original owner rmoved all of the R badges and put Quattro stickers on it? Quattro is Audi so if I were you, I would remove those stickers so that you don't look like a d-bag.

Ha, No the quattro stickers were removed before I bought it but when I washed it I could see a slight outline in the tint strip and lower rocker wax buildup. all evidence is gone now. Just saying that it appears a Dbag leased it prior and I should've looked closer before buying.

 

[The Fed]

Then you tuned it and destroyed your warranty. Anyway, did you replace the wheel sensor or wiring or resolve the fault?

 

[Mk7noob85]

Then you tuned it and destroyed your warranty. Anyway, did you replace the wheel sensor or wiring or resolve the fault?

Who needs a warranty. I appreciate the help. Have you had a similar issue?

 

[hans611]

Last month I had to replace my right rear ABS sensor.... 2016 Golf R....

The symptoms look just like mine, it might be an independent issue to your AWD/Haldex problem...

 

[scrllock]

lots of wheel hop when I disable TCS, just traction control and torque steer when I don't. I've had the car up on my quickjacks and everything spins with no strange noises. I have NOT been able been able to do the test where you lift the front end and leave the rear on the ground to see if the driveshaft spins under load.

I'm more interested in why the PWM signal to the haldex controller goes from 85% to 0% while the front wheels are still slipping (according to VCDS).

I would do that test. The clunk you were hearing could definitely be the bevel box.

And a failing ABS sensor will cause all sorts of issues, definitely fix that.

 

[Wastegate13]

I would do that test. The clunk you were hearing could definitely be the bevel box.

And a failing ABS sensor will cause all sorts of issues, definitely fix that.

Speaking of that test, does anyone have any insight as to why you need to do it with only the front in the air?

 

[sterkrazzy]

Speaking of that test, does anyone have any insight as to why you need to do it with only the front in the air?

I dunno, but that sounds sketchy af. What do you do when the rear wheels push the car forward because it's not as broken as you thought?

 

[scrllock]

Speaking of that test, does anyone have any insight as to why you need to do it with only the front in the air?

did you read the link?

 

[Wastegate13]

did you read the link?

If it’s the haldex repairs uk link then yes I did. I just don’t understand the point of only lifting the front wheels. The bevel box should drive the driveshaft at all times and the haldex should engage and disengage as needed.

 

[Mk7noob85]

I installed a new right rear wheel speed sensor and cleared codes. No change. I noted I had pending faults for steering clock spring and evap control valve. The only other issue is the exhaust valves (connectors damaged).

I still don't understand why the PWM signal going to the Haldex controller would work normally for 0.25 seconds then go to 0% I guess I'll correct the clock spring and evap valve, and crimp in replacement exhaust valve connectors ... then hope someone hits and totals the car. Being FWD sucks.

 

[Mk7noob85]

Finally took the golf to a shop. Found out the transfer case was the main issue. I didn't know the main gear was pressed onto a shaft with no key so over time they can slip on the shaft. Getting a reconditioned S3 transfer case installed along with some basic maintenance stuff. Will post an update once the repairs are complete.