Jump to content
CaddyInfo Cadillac Forum

pcm p1860 code. must pass nys emissions test.


Recommended Posts

hi. new here. was particularly happy with alot of the advice and help offered here. any help would be appreciated. i have a 2000 deville dhs with the northstar 4.6l motor. had a problem last time for new york state inspection that cost me over $900 to replace a leaking intake gasket between the manifold and mass airflow. 3 months later, service engine soon came on. now, tranny related.heres my codes, abs c1287h, ipc u1016h, ipm b0159c, ipm bo429c, pcm p0463h, pcm p1617h, pcm p1860c, rim c0660c. i do get the service stabillity sys on the display once in a blue moon. my gas gauge dosent read right, but track that with milage and fuel used(wich works pretty well). tranny shifts fine. goes into overdrive when in overdrive and pretty much shifts normally. driving in 3rd will set the SES light after a few miles. was told by an ex GM mechanic that its the tcc selenoid and is a major job. and he told me to drive it in 3rd, as when in overdrive with no lockup, tranny doesnt route the tranny fluid properly and could overheat it. ive seen posts that contradict that. will driving in overdrive with tcc locked off overheat tranny? if i just clear the pcm codes from the dash, the SES light goes out. does that clear everything? my New York State inspection is up and i have to get the emissions done. will clearing just the pcm codes clear everything? or is the emissions still good to hook up. thats my first worry, need the inspection. second ,is it actually the tcc pwm selonoid thats messed up, or could be related to the other codes i have. thanks in advance for any advice to get this inspected, then onto diagnostics for the tcc prob. thank you, thank you, thank you in advance.

Link to comment
Share on other sites


hi. new here. was particularly happy with alot of the advice and help offered here. any help would be appreciated. i have a 2000 deville dhs with the northstar 4.6l motor. had a problem last time for new york state inspection that cost me over $900 to replace a leaking intake gasket between the manifold and mass airflow. 3 months later, service engine soon came on. now, tranny related.heres my codes, abs c1287h, ipc u1016h, ipm b0159c, ipm bo429c, pcm p0463h, pcm p1617h, pcm p1860c, rim c0660c. i do get the service stabillity sys on the display once in a blue moon. my gas gauge dosent read right, but track that with milage and fuel used(wich works pretty well). tranny shifts fine. goes into overdrive when in overdrive and pretty much shifts normally. driving in 3rd will set the SES light after a few miles. was told by an ex GM mechanic that its the tcc selenoid and is a major job. and he told me to drive it in 3rd, as when in overdrive with no lockup, tranny doesnt route the tranny fluid properly and could overheat it. ive seen posts that contradict that. will driving in overdrive with tcc locked off overheat tranny? if i just clear the pcm codes from the dash, the SES light goes out. does that clear everything? my New York State inspection is up and i have to get the emissions done. will clearing just the pcm codes clear everything? or is the emissions still good to hook up. thats my first worry, need the inspection. second ,is it actually the tcc pwm selonoid thats messed up, or could be related to the other codes i have. thanks in advance for any advice to get this inspected, then onto diagnostics for the tcc prob. thank you, thank you, thank you in advance.

read down through the topics recently. I explained recently about fuel pumps and their easy change. $115 for a new pump and a half hour to change will fix your gas gauge. Or there are topics listed in that topic on how to use techron to clear the chemicals from your sensor that may work.

I also had a topic about 1860 and the TCC solenoid. Its a 10 hour job though ive heard some can do it less. But the shop says 10 hours. Ive been quoted at $1800 to fix plus a new converter and such. I kept it in 3rd to be safe but its not necessarily broke. Usually with the 1860 code you get a 700 something code. Well i didnt have the 700 something code. I guess just the tranny harness could need jiggled or cleaned to fix that 1860. Mine would throw the code every other time out but I only noticed symptoms once. So mine sure seemed erratic and something definately wasnt "broke" but maybe intermittant. Mine also never set the SES light off though.

* 1966 Deville Convertible

* 2007 Escalade ESV Black on Black

* 1996 Fleetwood Brougham Black on Black V4P -Gone
* 1983 Coupe Deville Street/Show Lowrider -Gone

* 1970 Calais 4dr Hardtop GONE
* 2000 Deville DTS - Silver with Black Leather and SE grille GONE
* 1999 Seville STS - Pearl Red GONE

Link to comment
Share on other sites

thanks for the info. i thought the pump replacement would entail dropping out the tank or worse. will check through the older posts then. my tranny shifts fine in all gears, even in overdrive. i get conflicting views on driving in overdrive though. a 20+ yr gm mech just advised that driving it in overdrive while the tcc is locked off is fine and wont overheat the tranny. will just lose 1-2 mpg. i was quoted 2200 to replace the tcc selenoid, the speed sensor(while its down, do it) and the new seals and torque convertor. not a bad price i guess for the work involved, but dont have that type of cash lying around. if i clear all codes, ses comes back on in 24 miles. if i just clear the pcm codes, ses light comes back on in 4 miles. im hoping i can clear just the pcm codes and that all other(ie, emissions) will still be good to get my nys inspection done. in ny you cant have the ses light on, and certain ckts have to be "ready" in order to get it done. guess ill have to keep my fingers crossed. thanks again.

Link to comment
Share on other sites

$2200, is way out of line for that job, you can get your tranny rebuilt for that much.

Logan had this code, here is a link for some background

http://caddyinfo.ipbhost.com/index.php?showtopic=12067

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Circuit Description

Ignition voltage is provided to the torque converter clutch pulse width modulation (TCC PWM) solenoid valve . The PCM controls the ON and OFF time of the solenoid by providing a ground through the output driver module (ODM) . The PCM uses a PWM duty cycle, in order to control application and release of the TCC. When the solenoid is commanded OFF, the PCM senses high volts. When the solenoid is commanded ON, the PCM senses low volts.

If the PCM detects a continuous open, short to ground or short to voltage in the TCC PWM solenoid valve circuit, then DTC P1860 sets. DTC P1860 is a type B DTC.

Conditions for Running the DTC

The system voltage is 8-18 volts.

The engine run time is greater than 5 seconds.

The engine is not in fuel cut off.

The TCC PWM solenoid valve duty cycle is 10% or less or 90% or greater.

Conditions for Setting the DTC

The TCC PWM solenoid valve feedback circuit indicates a continuous open, short to ground or short to voltage for 4.3 seconds.

Action Taken When the DTC Sets

The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.

The PCM inhibits TCC engagement.

The PCM inhibits 4th gear when the transmission is in hot mode.

The PCM freezes transmission adapt functions.

The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.

The PCM stores DTC P1860 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC

The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.

A scan tool can clear the MIL/DTC.

The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.

The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the PCM.

P1860.gif

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

thanks for the schem on that bodybyfisher. nyer too i see. i have checked fuses. all is good. with an ohm meter, can i test from the fuse side or should i go to the pcm side and read into the selenoid. thanks also for the 'out of line' $2200. i apreciate that. if i clear the pcm codes, will that reset everything? i know for the nys emissions you need so many ckts up and running normal. emissions are fine, just that p1860 code. everynow and then also get a p0463 or a p0471. intermitts. someone i know suggested pulling out the pcm plug and reseating it a couple of times to clean the contacts. also been told that the brake switch ties into this, as that is what can kick out the tc when its locked. sound reasonable? thanks much for the schematics. any idea what type of ohm reading to ground i should see? was told 4-11 is good. dont know if thats across or one side to ground though. have a great night guys. closed everything up for the night. start again tomorrow.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...