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Painful - PCM 1860 / 741 codes


jhall

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Hi all,

It's been a r e a l l y long time. Things were going well until a few months ago.

Have a 2000 and 2002 Devilles that are throwing PCM codes. The transmission oil is foaming slightly when the engine in running (both cars are doing this).

The 2000 is displaying the PCM 1860 code, then the 0741. The question is whether I can drive it in 3rd, let it throw the 1860 code and still pass inspection. Do all PCM codes cause an inspection failure for emissions? I have one year to fix, sell (or wreck) this one before the inspection expires. I believe this car can be fixed by replacing the A and B shift valves and the 741 code will also go away.

The 2002 is throwing the 0741 code outright. No 1860 code is showing. This one will pass inspection if the code is cleared and the car is driven in 3rd gear for a few days. Have done it for the last two years. looks like this may have more problems if it's not the pressure valve.

Now, to be ecologically minded with reduced guilt, I am considering dropping the engine / trans with the overhead support cross bar rig. I need to be sure I am replacing the proper parts. Would this be valves (shift and pressure?) or might it involve other parts to eliminate the problem

If other parts may be involved, I'd like to hear from the experienced guys. Don't want to pull these down and find out something else might also cause the codes after I reinstall everything(other than the brake switch).

One the fence about whether to buy something else versus fix them. If I pay to have these repaired, I hear I'll be out ~ $2K per vehicle. Cars are in great shape otherwise, but don't want to dump another wad of cash at this problem again later.

I was not too bent when the 2002 had the problem. Called GM customer service some time ago. This was no help. They wanted me to pay the dealer for the repair first and they "would review any claim" - right........., but when the 2000 went out as well, I lost lots of faith in GM - especially since the 2000 was repaired at 20K miles by the first owner (he had to fight with the dealer).

Look forward to hearing comments.

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The P1860 means that electrical contact is being lost or there is a short in the TCC wiring. This can be external to the transmission. The fact that a P0741 doesn't come up until after the P1860 tells me to look under the car and at the wiring before worrying about the transmission.

The 2002, which has the P0741 but not the P1860 is another matter. The solenoid could be sticking. A sticking solenoid may or may not require going basically into the transmission.

Replacing all three solenoids can be a DIY job. This kind of work requires an attention to detail and cleanliness that not everyone has, however. Misplacing or omitting a ball-bearing sized check valve will cause driveability problems, for example.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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The P1860 means that electrical contact is being lost or there is a short in the TCC wiring. This can be external to the transmission. The fact that a P0741 doesn't come up until after the P1860 tells me to look under the car and at the wiring before worrying about the transmission.

The 2002, which has the P0741 but not the P1860 is another matter. The solenoid could be sticking. A sticking solenoid may or may not require going basically into the transmission.

Replacing all three solenoids can be a DIY job. This kind of work requires an attention to detail and cleanliness that not everyone has, however. Misplacing or omitting a ball-bearing sized check valve will cause driveability problems, for example.

Thanks.

I'll check the easy stuff first, though both the 2000 and the 2002 are showing transmission fluid foaming at idle.

I don't have an issue with dropping the cradle and getting at it (though I hate spending hours on repairs). I pulled the engine / trans in my '97 Deville for time-sert, split case seal and trans filter / seal replacement (still running with the third owner).

I've got the FSM for the '97 and assume the trans series in the 2000 / 2002 is the same. Just need to be sure that the pressure and shift solenoids are properly identified before I dive into them.

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I trust you have seen Logans thread and findings, Mike

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

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All four of Logan's photos are down. Does anyone have copies?

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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We still have the pics. Pretty big job. The cradle has to drop about 10 inches to gain access to the trans side cover. Coolant system and AC system has to be opened up.

1860 causes false 741 code. I did measure ohms at the trans connector before going in. Pretty clear it was a bad solenoid inside.

I did price the job to the local Caddy dealer. Best I could get from them was about $1000.

Naw..I'll spend a Saturday doing it.

The rod / drop system worked perfect. Yellow arrow shows the bad TCC solenoid.

post-2-1253252714_thumb.jpg

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Someone else saw our post about the rod and drop system. They did it too and sent a picture. With Thanks for the idea..

post-2-1253253136_thumb.jpg

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Someone else saw our post about the rod and drop system. They did it too and sent a picture. With Thanks for the idea..

Thats me!

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

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