I have 2 issues in my car, maybe anybody have similar problems.

Overtemp issue. When driving hard, lot's of downshifting the temp rise very quickly once it's 90C, and at 110C the high temp warning light appears, aa few minutes later the CEL and SES light (gear indication is D5 or D6 or whatever gear is it in when the warning appears) appears, but the car can still drive normally (no slip/jerkiness)

Limp mode issue. This is happen even when I drive very slowly on the highway after about 1 hour drive. The temp is only 75C, no hard driving&kickdown. But when I press the gas the clutch slip (RPM rise quickly, but speed doesn't) But the car still can be driven If I accelerate very slowly or cruising. After a few minutes the CEL and SES light appears (gear indication is D1, the car enter the limp more, clutch not engage at all like in N position) I have to slow down, stop, and restart the car. After that I can drive the car but gear change is jerky.
Is the 2 issues related? Can I reset the CEL by disconnecting the battery (without going to the workshop)

I have 2 issues in my car, maybe anybody have similar problems.

Overtemp issue. When driving hard, lot's of downshifting the temp rise very quickly once it's 90C, and at 110C the high temp warning light appears, aa few minutes later the CEL and SES light (gear indication is D5 or D6 or whatever gear is it in when the warning appears) appears, but the car can still drive normally (no slip/jerkiness)

Limp mode issue. This is happen even when I drive very slowly on the highway after about 1 hour drive. The temp is only 75C, no hard driving&kickdown. But when I press the gas the clutch slip (RPM rise quickly, but speed doesn't) But the car still can be driven If I accelerate very slowly or cruising. After a few minutes the CEL and SES light appears (gear indication is D1, the car enter the limp more, clutch not engage at all like in N position) I have to slow down, stop, and restart the car. After that I can drive the car but gear change is jerky.
Is the 2 issues related? Can I reset the CEL by disconnecting the battery (without going to the workshop)

Adi I sent you an email with my thoughts :)

After checking with scanner, these code appears:
1. P1878 Gear Blocked (3rd)
2. P 1877 Gearblocked (2nd)
3. P 1879 ( Gearblocked (4th)
4. P 181E Clutch L Pressure Too low
Anybody experienced this before?

Limp mode issue. This is happen even when I drive very slowly on the highway after about 1 hour drive. The temp is only 75C, no hard driving&kickdown. But when I press the gas the clutch slip (RPM rise quickly, but speed doesn't) But the car still can be driven If I accelerate very slowly or cruising. After a few minutes the CEL and SES light appears (gear indication is D1, the car enter the limp more, clutch not engage at all like in N position) I have to slow down, stop, and restart the car. After that I can drive the car but gear change is jerky.
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4. P 181E Clutch L Pressure Too low


That is your problem ..

run without filter and see if you still get this issue ..
The rest of the codes are because of this

I install additional ARC cooler&pump, installed in sequence:
outlet trans - arc pump - arc cooler - stock cooler - inlet trans
Is the low pressure code appears because of additional the pump after the trans outlet makes pressure in trans lower?

I install additional ARC cooler&pump, installed in sequence:
outlet trans - arc pump - arc cooler - stock cooler - inlet trans
Is the low pressure code appears because of additional the pump after the trans outlet makes pressure in trans lower?

I may be outdated .. but this is the 1st time I heard there's an ARC cooler and pump combination ..

If you suspect this is the issue then you should disconnect the system.. but before you do that .. did you top up the fluid when you add the pump and cooler ?

Still can't believe there's one out from ARC because I would have known :p

Yes, I already top up the oil after cooler and pump installation.
The pump and cooler are from ARC. The cooler is originally made for R35 DSG as I told.

Yes, I already top up the oil after cooler and pump installation. The pump and cooler are from ARC. The cooler is originally made for R35 DSG as I told.

I think you have been told wrong by someone there Adi, as ARC dont make a transmission cooler for the R35 GTR. I believe if you remove this inline cooler and revert the car back to stock configuration your problems will be gone :)