tranny codes

[csledge]

I tried posting this in the driveline forum but got no response, so I hope y'all don't mind me posting it here.

I've noticed for a while now that my tranny likes to slip every now and then from 1-2, and slams into gear sometimes. It also acts like it doesn't want to move from a stop - instead of lurching forward as soon as my foot comes off the brake it just stays still, in fact, uphill it rolls downward like a manual. Torque converter?
The Check Engine light has been on so I decided to check it, and got all these:

P0740
P0785
P1860
P1870

All tranny codes.. So does it sound like my torque converter's just bad, or something more serious? I'm hoping I don't have to get a total rebuild. And I have to find a place that will work with my warranty company!

Thanks for the advice guys

Chris

[Mikz86TA]

PO1870
Member http://www.obdii.com/ubb/icons/icon1.gif posted 08-11-2006 06:36 PM http://www.obdii.com/ubb/profile.gif (http://www.obdii.com/cgi-bin/ubbmisc.cgi?action=getbio&UserName=reekor) http://www.obdii.com/ubb/edit.gif (http://www.obdii.com/cgi-bin/postings.cgi?action=editpost&forum=OBDII+(1996+and+up)&number=1&topic=003177.cgi&ReplyNum=000001&TopicSubject=Code+1870+on+4L60E+in+99+chevy+blazer ) http://www.obdii.com/ubb/quote.gif (http://www.obdii.com/cgi-bin/postings.cgi?action=reply&forum=OBDII+(1996+and+up)&number=1&topic=003177.cgi&TopicSubject=Code+1870+on+4L60E+in+99+chevy+blazer&replyto=1) General Motors Informative
GM service bulletin about code p1870 - GM service bulliten about code P1870
Posted By: NJBOB on 2/28/2006
Location: Collingswood, NJ

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
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
PO1860 = P1860 TCC PWM Solenoid Circuit Electrical
P0785 = P0785 Shift/Timing Solenoid
P0740 = P0740 Torque Converter Clutch Circuit
Looks like a TCC clutch cuircuit malfunction that is due to a common wear condition of the control valves in the ValveBody. In a nutshell, the fluid in the valve body will build pressure in the high-gear area which in turn causes the high gear lockup switch to activate. In turn, that will signal the TCC Clutch curcuit to activate and in turn activate the TCC clutch switch. Looking at the problem that has been determined by GM, the TCC Isolator and Regulator Valves are suspec to wear which is probably causing fluid leak in itself. That will basically bleed off the pressure on the valve causing it not to function properly and signal the TCC Curcuit like its suposed to. If I am reading and understanding it right, that is where I would begin. One thing leads to another. The computer is determining there are multiple malfunctions. Its up to experience to determine the root. IMO the 1st code is the root. I would find out id GM is recalling this issue. Seems they already have a fix-it-kit for it. Hope this helps =)

[87wildside]

Where do you get this from? I want to be smart!

[csledge]

also took a peek and my tranny fluid is brown.. looks about like thin motor oil. sounds like it's time to bite the bullet and take it somewhere :/