just got my car rescanned tranny code p1870

fastasshell · 10-24-2006, 01:29 AM

i just had my car rescanned and the codes removed (again )and they came back (again) but i have this code its a (p1870) i hope this will help us find out the problem that i am having. please let me know if this code helps because i have a chiltons book on the car but it only has a (p1860) code that is a torque converter clutch pwm solenoid control ckt thats what the book said the (p1860) code was. anyway please get back at me on this one to see if we can slap this problem i have right in the face.

Degtr · 10-24-2006, 07:21 AM

The p1870 should indicate a transmission slip. Are you feeling it slip in any gear or gears?

xeroinfinity · 10-24-2006, 09:59 AM

I just answerd your other post/thread Fastasshell.

IMO thiers something internaly going on causing it to slip.
Could be may things though.

Thier could hav been other DTCs stored in the history(if the battery wasnt disconected) that migth giv you more clues.

Chances are you are going to need to take it to a trans shop and hav them diagnose it, they hav the technology

xeroinfinity · 10-24-2006, 10:37 AM

TSB # 01-07-30-023A

This GM service bulliten might or migth not apply to your vehicle:

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

fastasshell · 10-24-2006, 12:36 PM

it looks like i may have to have my tranny rebuilt because when i changed my fluid&filter on the little magnet in the bottom of the tranny pan it had a gray tint like sludge on the magnet it kinda look like a graphite base.

xeroinfinity · 10-24-2006, 02:55 PM

That is what the magnet is for.

It varys tho on how much is to much.
Almost every one I hav ever changed looked to be about 1-2mm thick of material stuck to the magnet.
Some dont hav any...

Your troubles are with the valve body, as that TSB suggests.
So if you've never worked on these trany you will probly need it worked on. Couple hundred should get it taken care of though.

Good Luck.

maxwedge · 10-24-2006, 04:06 PM

Good info xeroinfinity, the latest repair for the p1870, if it is the common TCC valve and bore worn in the vb, is to resleeve the vb and permanently correct the problem, a new vb will wear the same as the old one unless GM has revised the design that was a problem on many of these aluminum units. Sonnax corp makes the kit to repair them.

xeroinfinity · 10-24-2006, 06:12 PM

I just replacd a VB on a 97' GP last week, even though they didnt list it in the TSB, it had the same symptoms.

Not that this is what fastasshell is having troubles with, though the only way is to take it apart.

What a mess

maxwedge · 10-24-2006, 07:42 PM

Quote:

Originally Posted by xeroinfinity

I just replacd a VB on a 97' GP last week, even though they didnt list it in the TSB, it had the same symptoms.

Not that this is what fastasshell is having troubles with, though the only way is to take it apart.

What a mess

Usually if scanned with a trans function scanner you can see slippage errors in lock up and the adaptive pressure being commanded to max, this indicates a slipping tcc or the tcc valve leaking pressure by, on application.

xeroinfinity · 10-24-2006, 08:16 PM

Quote:

Originally Posted by maxwedge

Usually if scanned with a trans function scanner you can see slippage errors in lock up and the adaptive pressure being commanded to max, this indicates a slipping tcc or the tcc valve leaking pressure by, on application.

This is true!

I'm still a bit new to the FWD automatics.
A buddy of mine used to help me with these things,
but he moved away, what a friend

JK

So what actually causes the VB to wear out so bad,
just the cheap aluminum and overall design ??

fastasshell · 10-25-2006, 01:03 AM

thank you guys very much for the awsome feed back that you have given me i have an appointment with the GM stillerships on thursday at 10 for a scan job. i hope the tranny scan is not to much. anyway i try to do the mechanic work on my cars myself. so is this a tuff job to do if i went and got the part and did it myself. or would you let GM do it because i would like to save money on this if i can.

xeroinfinity · 10-25-2006, 07:43 AM

Quote:

thank you guys very much for the awsome feed back that you have given me i have an appointment with the GM stillerships on thursday at 10 for a scan job. i hope the tranny scan is not to much. anyway i try to do the mechanic work on my cars myself. so is this a tuff job to do if i went and got the part and did it myself. or would you let GM do it because i would like to save money on this if i can.

If you hav never taken apart an automatic transmision I wont not attempt to do this repair .
Thier are a few things that could be wrong, and a shop that does these repairs will know exactly what to do.

Which they may pull the whole trans out to work on it.
That requiers a lift, and a couple days of work.

Good Luck at the stealership !

fastasshell · 10-25-2006, 12:04 PM

thank you very much it sounds like the stealership it is.

Brass_GA · 11-03-2006, 10:18 PM

Oh man I am glad I found this post. The symptoms described in that TSB match what I'm seeing in my '01 SE. Is there anyway I can get my hands on these TSBs? I'd like to take a copy with me when I head to the tranny shop.

Thank you xeroinfinity!

xeroinfinity · 11-04-2006, 10:35 AM

You can copy and paste that TSB or here are a couple sites that hav TSB's.
You can also do a search on google if you know the TSB #, it usually brings them up.

http://www.infotraxx.com/browse.php?Year=&Make=PONTIAC&Model=

http://www.carcomplaints.com/Pontiac/Grand_Am/1999/tsbs.shtml

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