The check engine light is on on my car i put in the computer a said the code p1870 but i don't know whats that mean

Code P1870...What does it mean??? - GM Forum - Buick, Cadillac ...

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Jun 9, 2005 - Location: Bloomington-Normal, IL 1997 SE ... Default Code P1870...What does it mean??? I got a CE light the other day, and this is the code that was read word for word: P1870 ... No TCC solenoid electrical DTC P0740 ... Code P1870 & Speedometer error, Hi_tork, 1992-1999, 4, 10-16-2011 04:08 PM.

DIYer? I recommend a repair manual from your auto parts store. It should provide a complete list of all error codes and likely repair methods. Otherwise find a competent repair shop, or your dealer. I googled your error code This is just one of the answers: http://repairpal.com/check-engine-light-with-code-p1870-057
I am sure you can do a better search since you know far more about the issues.

The fault is gone. What ever caused the problem is no longer there.
When the computer no longer detect fault it shuts off light. Maybe transmission had a short time problem

P1870 generally means that the transmission is slipping. P0420 relates to an issue with a vehicles catalytic converter. To know specifically what each code is, as it relates to your vehicle, you should take it to a local auto-part store (like AutoZone and have them pull the codes off of your vehicle. At auto part stores, they generally do this service for free and it is pretty quick. Regards ~ JD

I didn't locate that one you posted, but this is the closest thing I ca e up with P1870 Transmission Component Slipping/ Transmission Mechanical Transfer Case 4x4 Switch Circuit Failure I don't know if that pertains to your vehicle since the info needed isn't posted on your question, but if you reply to this post, I will assist you more

I also have a 99 Lumina and code p1870 means: Transmission Component Slipping/ Transmission Mechanical Transfer Case 4x4 Switch Circuit Failure Now we both know theres no 4x4 in these cars. So I'm going to try to find out about this and try to figure out why the PCM showed this code. When I do, I'll put it on my profile.

The code description for P1870 is "transmission component slipping" and usually means that the computer has detected a difference between what the input speed is and output shaft speed should be under certain conditions and tagged it as a slipping component. Usually it means that a clutch pack [usually direct drive clutch] or band isn't holding under a load and has started to slip. Sometimes the slippage can be observed on a scan tool during a road test but if the slippage is bad enough it may be noticable just driving it. Low transmission fluid level could cause this problem so make sure you check it before going any further. If it turns out that there is interal slippage then the transmission would have to come out and be repaired.

This GM service bulliten might apply to your vehicle:

TSB # 01-07-30-023A
Harsh 1-2 Upshift, SES, MIL, or CEL Illuminated, DTC P1870 Set (Replace Valve Body)
1996 Buick Roadmaster
1996 Cadillac Fleetwood
1996-2000 S10 Blazer
1999-2000 Cadillac Escalade
1996-2000 Chevrolet Camaro, Corvette
1996-2000 Pontiac Firebird
1996-2000 Chevrolet and GMC Light Duty Truck Models
1996-2000 Oldsmobile Bravada
with 4L60-E Automatic Transmission (RPO M30)
Built Prior to January 15, 1999 (Julian Date 9015)
This bulletin is being revised to update the Parts Information

Please discard Corporate Bulletin Number 01-07-30-023 (Section 07 -- Transmission/Transaxle).
Condition
Some customers may comment on a harsh 1-2 upshift and the Check Engine Light or Service Engine Soon indicator is illuminated.
Diagnosis
Typically, these vehicles will have been driven more than 32,000 km (20,000 mi) before this condition occurs.
The scan tool may show a DTC P1870 set as a history code.
A harsh 1-2 shift or DTC P1870, caused by wear in the control valve body, may be difficult to duplicate when the transmission temperature is below 93°C (200°F).
Cause
The condition may be due to wear in the control valve body. This wear occurs in the bore that contains the TCC isolator and regulator valves, and results in poor, or no, TCC apply

Important
DTC P1870 is a type B code. The conditions for setting the P1870 DTC must occur on TWO CONSECUTIVE TRIPS (ignition cycles, with a drive cycle) before setting a P1870 history code.
When the conditions for setting DTC P1870 are met (first trip), the PCM commands maximum line pressure and harsh 1-2 shifts are the result.
This may result in a harsh 1-2 shift with no history code if the conditions for setting the DTC required for the second trip are not met, on two consecutive trips (Ignition cycles, with a drive cycle).

When the conditions for setting the DTC are met, on the second consecutive trip, a DTC P1870 is stored as a history code.
When the P1870 code is stored, the PCM will turn on the Service Engine Soon (SES), Check Engine Light (CEL), or Malfunction Indicator Lamp (MIL).
Correction
Install a control valve body with the revised TCC regulator and isolator valves. These valves are used in all transmissions produced after January 15, 1999 (Julian Date 9015), and all of the service parts currently available through GMSPO contain revised TCC regulator and isolator valves.

Important
If all of the following conditions are true, it is not necessary to rebuild the transmission or to replace additional transmission components beyond the control valve body.

Transmission operation is normal before the transmission reaches operating temperature, or before DTC P1870 is set (no slips, flares, or missing gears).
The torque converter is not blue or overheated.
The transmission fluid is not burned or has no burned odor.
The transmission fluid pan contains no abnormal debris (clutch material, bronze, brass, or metal fragments

yes, when you burn your transmission fluid, its just like when you burn your motor oil. Lower vescosity means more friction. more friction, more heat, more heat messes with your sensors inside the trans causing them to send a code to the ecm. do a filter change and transmission flush. clear the code and retest.

no but a low fluid level could cause a slip telling the ecm there is a slip top it off then clear the code and drive a few miles if this code comes back i would say there is internal damage to the tranny