drjonez

I've used my 2011 Q7 TDI to tow a 5800 lbs travel trailer regularly for three years, with no issues. I recently deleted and am running Malone Stage 2 SW. On my first towing trip (200 miles each way) since the delete, 1h in towing at 72 MPH in manual mode, the cruise dropped off and the trans temps began to climb and I was down to ~4 gears. VCDS showed this (full data pasted for completeness):

Address 01: Engine (J623-CATA) Labels:. 059-907-401-V2.clb
Part No SW: 4L2 910 401 HW: 4L0 907 401 D
Component: 3.0TDI FSA X18 0009
Revision: 54X18--- Serial number:
Coding: 2A2A4012253600050000
Shop #: WSC 00000 000 00000
ASAM Dataset: EV_ECM30TDI0114L2910401 002008
ROD: EV_ECM30TDI0114L2910401_002.rod
VCID: 61C82F71701EC28E64-8034

1 Fault Found:
2937 - Implausible Data Received from Transmission Control Module
U0402 00 [032] - -
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 220389 km
Date: 2021.06.02
Time: 13:20:24

Engine speed: 1912.00 /min
Normed load value: 43.9 %
Vehicle speed: 112 km/h
Coolant temperature: 98 ∞C
Intake air temperature: 36 ∞C
Ambient air pressure: 970 mbar
Voltage terminal 30: 14.260 V
Unlearning counter according OBD: 40
Accelerator pedal travel: 0.00 %
Accelerator pedal: sensor voltage 1: 742.6 mV
Accelerator pedal: sensor voltage 2: 371.2 mV
Accelerator pedal: switch positions-Bits 0-7: 1
Starter control: Interlock- or P/N-signal-Bits 0-7: 1
Limitation: torque: 600.0 Nm
Control Module temperature: 43.9 ∞C

Readiness: 0 0 0 1 X

-------------------------------------------------------------------------------
Address 02: Auto Trans (J217) Labels:| 0C8-927-750.clb
Part No SW: 0C8 927 750 S HW: 0C8 927 750 S
Component: AL1000 AISIN 001 3408
Serial number:
Coding: 00B178
Shop #: WSC 29134 003 104857
ASAM Dataset: EV_TCMAL991031 002112
ROD: EV_TCMAL991031_002.rod
VCID: 3C76BE05B73CCF6617-8068

2 Faults Found:
12860 - Torque Converter Clutch
P0741 00 [032] - Stuck OFF / No Power being transferred
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Reset counter: 40

Engine speed: 1950.0 /min
Transmission input speed: 1860 /min
Transmission output speed: 2700 /min
Engine torque: 512 Nm
Transmission fluid temperature: 90 ∞C
Accelerator position: 92.4 %
Clutch_C1: Open
Clutch_C2: closed
Clutch_C3: Open
Clutch_C4: Open
Clutch_B1: closed
Clutch_B2: Open
Lock Up Clutch: closed
EOP target revolution: 65534 /min
EOP actual revolution: 65279 /min
Engine Speed signal Current: 65279 /min
EOP failure status with EOP without HV 1: Motor normal stop
EOP target current: 65278 mA

12868 - Torque Converter Lockup Clutch
P1811 00 [008] - Preliminary Over-Temp Stage Reached
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Reset counter: 179

Engine speed: 3210.0 /min
Transmission input speed: 2280 /min
Transmission output speed: 1890 /min
Engine torque: 528 Nm
Transmission fluid temperature: 98 ∞C
Accelerator position: 82.4 %
Clutch_C1: closed
Clutch_C2: closed
Clutch_C3: Open
Clutch_C4: Open
Clutch_B1: Open
Clutch_B2: Open
Lock Up Clutch: Open
EOP target revolution: 65534 /min
EOP actual revolution: 65279 /min
Engine Speed signal Current: 65279 /min
EOP failure status with EOP without HV 1: Motor normal stop
EOP target current: 65278 mA

Being a season VAG enthusiast, I looked @ the codes and said "huh, I guess the TCU went out to lunch for a bit and blamed the TCC", cleared the codes and went on my merry way. On my return trip I left it in D and suffered with the droning exhaust and had no issues. On the next towing trip (120 miles each way), the trip out was fine no issues, drove in D. 1.5h into the trip back, cruise dropped out again and I was down gears. I pulled over, turned the car off and turned it back on, the trans was back with all gears and shifting normally. This happened a few more times, I did finally end up with a CEL and the VCDS scan showed this:

Address 01: Engine (J623-CATA) Labels:. 059-907-401-V2.clb
Part No SW: 4L2 910 401 HW: 4L0 907 401 D
Component: 3.0TDI FSA X18 0009
Revision: 54X18--- Serial number:
Coding: 2A2A4012253600050000
Shop #: WSC 00000 000 00000
ASAM Dataset: EV_ECM30TDI0114L2910401 002008
ROD: EV_ECM30TDI0114L2910401_002.rod
VCID: 61C82F71701EC28E64-8034

2 Faults Found:
2937 - Implausible Data Received from Transmission Control Module
U0402 00 [040] - -
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 3
Mileage: 221830 km
Date: 2021.06.20
Time: 13:57:29

Engine speed: 1942.00 /min
Normed load value: 40.4 %
Vehicle speed: 113 km/h
Coolant temperature: 96 ∞C
Intake air temperature: 32 ∞C
Ambient air pressure: 950 mbar
Voltage terminal 30: 14.400 V
Unlearning counter according OBD: 40
Accelerator pedal travel: 0.00 %
Accelerator pedal: sensor voltage 1: 742.6 mV
Accelerator pedal: sensor voltage 2: 371.2 mV
Accelerator pedal: switch positions-Bits 0-7: 1
Starter control: Interlock- or P/N-signal-Bits 0-7: 1
Limitation: torque: 600.0 Nm
Control Module temperature: 33.2 ∞C

10577 - MIL Request Signal Active (Check TCM for errors too!)
P1624 00 [047] - -
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 6
Fault Frequency: 1
Mileage: 221869 km
Date: 2021.06.20
Time: 14:20:23

Engine speed: 1753.00 /min
Normed load value: 4.3 %
Vehicle speed: 107 km/h
Coolant temperature: 95 ∞C
Intake air temperature: 34 ∞C
Ambient air pressure: 950 mbar
Voltage terminal 30: 14.340 V
Unlearning counter according OBD: 40
Engine status: COENG_RUNNING
Engine status-Test_Program_Co Eng st COMPU VERB UBYTE: 3

Readiness: 0 0 0 1 X

-------------------------------------------------------------------------------
Address 02: Auto Trans (J217) Labels:| 0C8-927-750.clb
Part No SW: 0C8 927 750 S HW: 0C8 927 750 S
Component: AL1000 AISIN 001 3408
Serial number:
Coding: 00B178
Shop #: WSC 29134 003 104857
ASAM Dataset: EV_TCMAL991031 002112
ROD: EV_TCMAL991031_002.rod
VCID: 3C76BE05B73CCF6617-8068

1 Fault Found:
12860 - Torque Converter Clutch
P0741 00 [168] - Stuck OFF / No Power being transferred
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Reset counter: 41

Engine speed: 1950.0 /min
Transmission input speed: 1860 /min
Transmission output speed: 2700 /min
Engine torque: 480 Nm
Transmission fluid temperature: 86 ∞C
Accelerator position: 85.6 %
Clutch_C1: Open
Clutch_C2: closed
Clutch_C3: Open
Clutch_C4: Open
Clutch_B1: closed
Clutch_B2: Open
Lock Up Clutch: closed
EOP target revolution: 65534 /min
EOP actual revolution: 65279 /min
Engine Speed signal Current: 65279 /min
EOP failure status with EOP without HV 1: Motor normal stop
EOP target current: 65278 mA

So, it looks like there is an issue....but the question is where. I'm familiar with the TCC and its role and certainly it not locking up is why the trans temps climbed. My Q7 has the dieselgate fix done before I bought it, I changed the transmission coding to Cayenne last year mid-tow season, the only thing that has changed since towing last year is the delete/tune and a trans oil change with Idemitsu TLS-LV. Questions:

• Has anyone seen the TCC TCM code or the implausible data ECU code? If so what fixed it?
• Has anyone had issues towing post delete? Terrain is rolling midwest hills.

To me, this seems to point to some incompatibility in the ECU-TCM communication post-fix and post-tune or perhaps a flakey TCC solenoid. I'm hoping it is the former and not the latter, since it appears the TCC solenoid can only be replaced with a valve body swap. I will be reaching out to Malone tomorrow. I have a hard time believing it is something else with the transmission, mostly because it is a pretty robust trans and my Q7 was well maintained prior to my ownership. TIA!

drjonez

Bumping this up- it seemed to be related to towing with the stage 2 tune, I've rolled back to a stock delete tune and that was fine until it wasn't- ran into the code for the first time on the stock tune over the weekend. Has anyone seen this? TIA!

Pothole5000

I don't have a TDI, but I know @dreadlocks does with a delete and tows with it.

Did Malone have anything to say when you asked them?
Your trans temp don't seem that high to me, but I have only towed little trailers.

Did you happen to check what your exhaust temp was?

drjonez

Yup, I've talked to dread about this a bit as well as googled all over and searched through clubtouareg. I've reviewed and cleaned all TCU and trans connections, all look good. The only time I get the error is during extending towing of my 5800 lbs travel trailer (that I've been towing for years).

Trans temps from the sample data above don't capture the whole picture- I saw 260F on my Scanguage. No idea what EGTs area since Scangauge refuses to work with me to get the right Xcodes for the gen 1.1 TDI.

From Malone- "We have never had this happen on another vehicle but a smaller percentage of customers tow, some do tow enclosed trailers though for hours at a time."

frqflyer

Do you always tow heavier loads in D, especially non flat terrain? IIRC the 8 speed Aisins only lock up to 6th gear. I'm just wondering if the extra power you have is letting you carry a gear higher than you normally could and overheating the trans.

I had that happen on a truck that I couldn't carry overdrive on with a load of I wanted to and ran that route many times. Had a big tail wind one day on the highway for a hour that was allowing me to be in overdrive and wasn't thinking anything of it or paying attention to the trans temp gauge until I stepped on the pedal on slight incline, felt a tiny slip, looked down at guage like WTF?! and by then the damage was done.

If I read your post right I think you said trans fluid was reading 260? Yea, that is way too high. Even on a 100F day on my truck that has a transcooler I only see 200F if I'm pulling a big load up a long 6 or 7% grade with the engine pegged in a lower gear.

I would siphon out a little of the ATF to see what it looks like. When I had that aforementioned issue I can't recall what the temp was, but I think the guage maxed somewhere around 260 to 280F, so it was at least that high (and probably much higher). The ATF was burnt and smelled so foul the guy who worked on it probably needed a respirator.

Not saying this is your problem, because the faults make it seem it is related to solenoid but just sharing anecdotal experience. I know Dread tows all over and hasn't had a problem. If the aisin really doesn't lock up past 6th it might be worth seeing if he knows what gear he runs in. Even in D it might not be going past 6 for prolonged periods except on forgiving terrain for him while yours is seeing 7 or 8 a lot and/or hunting.

Hunting in auto while I am hauling will spike the temps on my truck so I pick the gear that it can carry and leave there until the terrain changes enough that a different gear is warranted. I have to drive that thing like a manual when I am driving through anything but flat land with a load, lol. I haven't towed much with the Q7 and never anything other surface streets so I can't offer any direct experience unfortunately.

drjonez

The only time the temp spikes is when the solenoid drops out and you lose lock up, based on that I would say the TC is locked in all gears. Normally it sits around 192F or so. Interestingly when towing on the stage 2 tune, the trans temp is ~5F higher for a given speed/grade/load.

I changed the trans fluid after the high temp trip, so it is running fresh fluid at this point. This is a bit frustrating since towing is the main reason I bought the Q7....and it is really good at it.

dreadlocks

I tow a bigger trailer up rougher terrain, full delete, more power/torque, same gearbox oil, but 8spd instead of 6spd.. just did Wolf Creek Pass this last weekend when ambient temps read high 90's before I started, and for first time ever saw coolant temps climbing off-nominal.. checked oil temps on MMI and it hit 300F, once I kicked it down to 5 under the speed limit everything went back to normal.. came back up the steeper side a few days later in cooler temps and staying 5 under the whole time and engine oil temps never got past 280F, I'm changing the oil today.. I only put it into manual mode when I'm coming down a pass and need it to not upshift on me.

I'd check the fluid levels on the gearbox first, make sure it's not over or under filled.. if its been overheating the gearbox mebe just outright change it all.. if that does not yield good results then I'd find a good indy mechanic familiar w/toyota gearboxes to take a stab at it.. Automatics are hydraulic wizardry that I dont **** with, Its one of the few things I'd rip out and let someone else fix.

drjonez

We have the same transmission- the 8 speed Aisin. Fresh fluid is in there and correctly filled. The issue only cropped up after the tune and delete. I don't remember if the generation of the ECU is the same between gen 1.1 and gen 2.

Unfortunately there are no good indy mechanics around with any knowledge of VAG or the Aisin gearboxes. The internet is my only hope...

dreadlocks

there may be a correlation with getting the tune but I don't believe it has any causation, if a torque converter is having issues locking up then adding more torque to the mix wont make things better.. just more apparent.

joels2k

These TR80 converters are of the captive clutch type, similar to a GM 8 speed. They do wear with mileage and sometimes for no reason at all. I would recommend replacing it or having it rebuilt by a local company if there are any decent companies around. It's not a bad idea to catch it earlier before the clutch flakes off and jams up the valve body.