jmms

HiI'm new to this forum

We just bought a Very clean, one owner, 1997 Express convertion van with only 51k miles on it. The van is in mint condition and runs great. We love it! The only problem we have with it is the "service engine light" comes on. I had a shop read the code and they said it's a P1870 code. Talked to another guy and he said that's the transmission converter clutch slip code. This might explain to it shift hard from 1 -2 gear?

Anybody else have this problem??

John86

TCC System Symptom Table



Symptom

Causes


TCC SLIP (100RPM SLIP)
[align=left]



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Check for bronze bushing material in the pan and filter. If bronze material is present, then the stator bushings (234) and turbine shaft (241) should be replaced (Bronze bushing may turn black with an acrid odor).[/align][align=left]



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The turbine shaft and housing (621) should be replaced if damaged.[/align][align=left]



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In rare instances, it may be necessary to check for an overheated torque converter (24) (Blue and/or distorted converter).[/align][align=left]



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TCC solenoid (66) - Perform leak check.[/align][align=left]



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Converter clutch valve (224) in pump should be checked for 13mm (0.500in) of bore travel without binding.[/align][align=left]



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Turbine shaft O-ring seal (618) cut.[/align][align=left]



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Turbine shaft hole not drilled to full depth. This concern can be checked by squirting trans fluid through the turbine shaft hole to check for full flow. This is a low mileage failure.[/align]


NO TCC APPLY (300RPM SLIP)
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Converter clutch valve (224) stuck closed (Check for debris in valve bore).[/align][align=left]



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TCCPWM solenoid (396) broken/cracked. Visually inspect solenoid.[/align][align=left]



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TCC solenoid (66). Perform leak test.[/align][align=left]



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Turbine shaft O-ring seal (618) omitted.[/align]


TCC SLIP WITH STALL STUMBLE

Converter clutch valve (224) stuck open (TCC is applying).


INTERMITTENT TCC, OK COLD, SLIPS HOT
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TCCPWM solenoid (396). Leak test solenoid.[/align][align=left]



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The TCC regulator apply valve (380) and/or converter clutch shift valve (224) may be sticking/side-loading. It is possible there will not be any damage to the valve upon inspection. Transmissions produced after 2/1/98 will have a groove cut into the spring end of the regulator apply valve. This design is to help float the valve in its bore (replace valve body assembly).[/align]


Internal Transmission Symptom Table



Symptom

Causes


3RD OR 4TH GEAR SLIP
[align=left]



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3-2 downshift solenoid (394) ball seat retention failed. Leak test solenoid. Usually associated with a 3-4 clutch/band worn.[/align][align=left]



•
3rd accumulator retainer and ball assembly (40) leaks. Test for proper check ball operation. Usually associated with burned 3-4 clutch.[/align]


NO 4TH OR SLIPPING 4TH
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Check ball in the wrong location or extra check ball that has dropped behind the spacer plate during trans assembly. The extra check ball can block the 4th apply servo feed.[/align][align=left]



•
Clutch orifice cup plug (238) not fully pressed in.[/align]


SLIP/FLARE IN ANY GEAR

Pump slide inner spring (207) or outer spring (206) omitted causing a slow slide response.


NO 3RD

Clutch orifice cup plug (238) blown out.


HARSH 1-2 UPSHIFT

4-3 sequence valve (383) stuck in bore by sediment.


NO 2-3 UPSHIFT

2-3 shift valve (368) or 2-3 shuttle valve (369) stuck in bore by sediment.


NO 3-4 UPSHIFT

3-4 shift valve (385) stuck in bore by sediment.

jmms

I was also told that by blocking the TCC regulator valve is a legitimate way to correct a repeat P1870 code.

btotheh33

p1870 is "Internal Transmission componet Faliure". It propably needs to come out and be overhauled.

1999nbmZ

So, I just picked up my Tahoe from having the trans rebuilt Monday afternoon, and I get this code on Tuesday night. Not very impressed. At least it's their dime, I'd be screaming pissed if I'd done it myself...

Alientranz

1870 is the most common code set by the 4l60E transmission. More times than not you can fix the problem without removing the unit, and in your case since you only have 50k on it, I'd say your chances for sucsess are pretty good. 1870 is a transmission performance code which is set when a slip is detected. Most of the time it is picking it up from the torque converter. When this code sets it jacks up the electronic presure control soloniod to try and protect it from slipping, which is why you feel a harsh 1-2 shift. Blocking your torque converter valve in the valve body is one common way to fix this problem, but the best thing to do is to install a transgo jr. shift kit. The kit comes with a new valve and spring that replaces your old set up and compensates for the normal wear that occurs in the bore. That system was junk. What chevy was trying to do was make lock up come on gradually so you don't feel lock up, so it slowly applies lockup letting the lockup clutch slip until it gives the command for 100 percent lockup. If you are mechanically inclined it's really not that hard to do on your own. Our shop charges around 500 dollars to do the service, so expect somewher in that range if you decide to take it to a local trans shop. Just something to think about before you condemn the unit.

kattartt

see my post in new member- son has chevy s10 same problem we replaced spring in tcc regulator-code came back awhile later -we just put in a tcc apply valve and pump 3 days ago it appears to be working.