Got P1870 A4 Slips
Thread Starter
Racer
Joined: Jan 2005
Posts: 375
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From: Montreal Drive it like you test it !
Got P1870 A4 Slips
Got P1870 today on driving 200 miles on regional road at 50 mph. Tranny oil temp was 225. I had to reset the code at every stop before I accelerate to reduce pressure so shifts are not too hard. Oil was changed last year and I never had a leak since.
I took the freeway on my way back at 75 mph and did not get the code. Tranny oil was 195. I think this is normal since the manual says that the code is generated only from 35 to 65 mph.
Anyway, the question is what is the solution to this? Should I plan a new TC and complete rebuild? Or only TC?
Can I keep it like that for a couple of months? I do 90% freeway. I just rebuilt my Bike tranny this week. I’m not ready for a Vette tranny…. I have work do to on the hou$e.
Stock 97.
I took the freeway on my way back at 75 mph and did not get the code. Tranny oil was 195. I think this is normal since the manual says that the code is generated only from 35 to 65 mph.
Anyway, the question is what is the solution to this? Should I plan a new TC and complete rebuild? Or only TC?
Can I keep it like that for a couple of months? I do 90% freeway. I just rebuilt my Bike tranny this week. I’m not ready for a Vette tranny…. I have work do to on the hou$e.
Stock 97.
Intermediate
Joined: Dec 2005
Posts: 41
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From: Bel Air Md.
You should check your trans fluid first. This is not easy to do without a lift.
If the fluid is dark and burnt smelling you need an overhaul. 
Most of the time this code is caused by a sticking valve in the valvebody. If the fluid is burnt you will need both a valvebody and a complete overhaul. If the problem is only the valvebody and you continue to drive it you will burn up the clutchs. To proprerly diagnois you need a scan tool to monitor tcc slip speed. If you are not running a stock gear ratio this can also set this code if it has not been reprogramed. Good luck, I would not wait to have this checked out.
If the fluid is dark and burnt smelling you need an overhaul. Most of the time this code is caused by a sticking valve in the valvebody. If the fluid is burnt you will need both a valvebody and a complete overhaul. If the problem is only the valvebody and you continue to drive it you will burn up the clutchs. To proprerly diagnois you need a scan tool to monitor tcc slip speed. If you are not running a stock gear ratio this can also set this code if it has not been reprogramed. Good luck, I would not wait to have this checked out.
Thread Starter
Racer
Joined: Jan 2005
Posts: 375
Likes: 0
From: Montreal Drive it like you test it !
Thanks a lot LS6 TECH. 
I will check the fluid. Last time I was able to do it with four jack stand. I followed your recommendation and went to a local tranny shop. They can plug a snap on scan tool to monitor tcc slip.
I have not got the code for the past two days. Next time it appends, I will have the scan tool install.
I hope that the problem is a sticky valve. I read in the manual and it looks like we can remove the valve body without having to remove the tranny from the car. They quoted me $1500 for complete rebuild + tcc if I bring them the tranny. I removed transmission on my C3 & C4. That will be the first time on a C5 and a lot more job…..
I will check the fluid. Last time I was able to do it with four jack stand. I followed your recommendation and went to a local tranny shop. They can plug a snap on scan tool to monitor tcc slip.
I have not got the code for the past two days. Next time it appends, I will have the scan tool install.
I hope that the problem is a sticky valve. I read in the manual and it looks like we can remove the valve body without having to remove the tranny from the car. They quoted me $1500 for complete rebuild + tcc if I bring them the tranny. I removed transmission on my C3 & C4. That will be the first time on a C5 and a lot more job…..
Safety Car
Joined: Aug 2000
Posts: 4,154
Likes: 1
From: Murphy TX
Cruise-In II Veteran
I'd add that the code can take a while to set, so don't assume things are okay just because it hasn't set yet. Temps will definitely go up if you're driving at highway speed with the converter unlocked (i.e. the code is set.) I would watch the temps like a hawk. You can clear the code via the DIC while driving.
