I just had the code cleared - P1870 - which says:

Transmission automatic 4-wheel drive indicator (Lamp) Circuit Short to Battery

The other day in traffic the shifting on the tranny got REALLY hard, but after getting to work and it sitting all day I haven't had any trouble since (2 days ago). I had Autozone check it and clear it and it's gone. Just looking for a translation of what the code description is really telling me.

Thanks.



------------------
99 Z28; Navy Blue Metallic
3.23 axle; A4;
SS Hood; Dynomax Ultra Weld muffler; Whisper lid
Chrome wheels& badges, red Camaro fills; T-tops; leather
Mohr Softball
Mohr Racing

 

P1870 Transmission Component Slipping

Circuit Description

The powertrain control module (PCM) monitors the difference between engine speed and transmission output speed. In D3 drive range with the TCC engaged, the engine speed should closely match the transmission output speed. In D4 drive range, with the TCC engaged, the TCC slip speed should be 20 to +40 RPM. The table above indicates solenoid states and transmission components that apply, during 4th gear, with the TCC commanded ON.

When the PCM detects excessive TCC slip when the TCC should be engaged, then DTC P1870 sets. DTC P1870 is a type B DTC.

How old is the tranny fluid?

 

I had a Yank3000 and the tranny fluid changed about 4 months ago. No problems during that 4 months til recently. I had the code cleared, but it came back.

 

with a P1870 DTC. you will need to pull the trans pan off and look for metal in the pan and on top of the filter. If metal is found you will need to rebuild/replace the trans. If no metal is seen in the pan, you can usually get by with replacing the valve body only. 1870 is a very expensive DTC to have. good luck

 

FYI, I had the SAME EXACT problem/code. I was driving down to PA to see my aunt, and on highway, no problem. When I slowed down to get gas, and started going, it shifted into 2nd HARD like I had a shift kit or something. I mean it was throwing me back in my seat. Sent off an ses light. I bought a 210 dollar code scanner from pep boys, go that code, cleared it, and no problems since. Just clear the code and see if it comes back. Who knows. Do you have any type of gear re-calibrator on your car? I did from Jet and it SUCKED. MAJOR problems, so got rid of it. Need to reprogram for my gears sometime. I have yet to get around to that. Anyways, good luck.

Later.

 

Just an fyi on this thread. I had the valve body replaced ($700) and.............P1870 came back a week later ! SES on.

Gotta find time to take it back to the dealer.