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Transmission won't engage

M

meritt

New member
Hi Everyone, my son and I (6 months ago) completed an engine transmission swap in his Grand Prix. We purchased a complete drop out L67 engine/trans from Morad autoparts when his L36 died.

It has been running fine but yesterday he was pulling out onto the highway and just got up to about 60 MPH when the car shuddered and then acted as if it were in neutral. The fluid level is fine, looks clean, and smells good but the car is failing to engage in any gear and is reading the codes P1810 and P1860.

So far I find that:
Code P1810 TFP (Transmission Fluid Pressure) Valve Position Switch Circuit
- may indicate an electrical problem?

Code P1860 - TCC PMW Solenoid circuit electrical
- would also seem to indicate and electrical failure?

I was able to verify 12 volts on the pink (I think connector E) wire on the trans electrical plug so that seems to be OK.

Since we did the swap I think it is completely possible that we damaged the wiring somehow and I would prefer fixing that to a trans rebuild. I am even game for solenoid replacement if I can determine that is the culprit.

The transmission shop just said we don't know til we tear into it.... translated as $$$$$$

it seems strange to have a sudden catasrophic failure like this to me as prior nothing seemed to be slipping etc but the transmission shop seemed to be leaning that way?
thanks for any assistance you can offer.
Merritt
 


Mine just started doing the same thing about a week ago.

video-2012-06-29-14-04-42 - YouTube

At first I thought I had some sort of ignition/fuel issue. It seemed when the car gets warm this happens (video above). Step on gas, engine just bogs down, builds boost, etc. If I pull off the road and shut the car off for a few minutes, it works fine upon restart. This has been happening for nearly a year, and ever since I first bought the car in '05, it's had the TCC stuttering issue at highway speed with a bit of throttle applied (RPM bounces up and down a few hundred instead of downshifting).

This past Saturday it started doing the stuttering thing again, so I pulled into a neighborhood to shut it off. I came up to a stop sign, figured I was too close so I put it in reverse (from drive, haven't been to "park" yet) to get some space between myself and the intersection. No reverse. Back to drive - now no drive either. Shut the car off, re-started a few minutes later, still not engaging in any gear. Tried drive, 3, 2, reverse, etc. Every gear is neutral. I replaced the range switch, but that wasn't the problem. Got the car home (yay AAA), and unhooked a fluid line to check for flow. No fluid flow. Dropped the pan to change the filter, plenty of fluid (was full on dipstick before I drained), and the pan/fluid was surprisingly clean. No debris in the pan, fluid wasn't burned. Just looked like old fluid, still a slight pinkish tint and no weird smell. Roughly 200k on trans, and about 110k since last fluid change, although I did add a few quarts of new fluid last year when I installed an external cooler thinking it was the tranny just getting hot and causing this issue. :-/

Replaced the filter, added new fluid, still nothing. Trans won't engage any gear, and no pressure at the cooler.

Oil pump? Torque converter? I have no idea where to go from here, and don't want to rip it out to replace something internal, only to discover it isn't the issue. Hoping it's a simple fix, but it's looking like I'll be dropping the trans and taking it to a shop.

Any ideas?

Cliff's notes:
Not engaging any gear
replaced range switch, no dice
no fluid flow/pressure at trans cooler
replaced filter and fluid, no dice
many beers were had.

EDIT: Also, no codes. Granted, I don't have a Tech II, but I do have the DHP and a bluetooth OBD reader for my phone.
 
Peder said:
Mine just started doing the same thing about a week ago.

video-2012-06-29-14-04-42 - YouTube

At first I thought I had some sort of ignition/fuel issue. It seemed when the car gets warm this happens (video above). Step on gas, engine just bogs down, builds boost, etc. If I pull off the road and shut the car off for a few minutes, it works fine upon restart. This has been happening for nearly a year, and ever since I first bought the car in '05, it's had the TCC stuttering issue at highway speed with a bit of throttle applied (RPM bounces up and down a few hundred instead of downshifting).

This past Saturday it started doing the stuttering thing again, so I pulled into a neighborhood to shut it off. I came up to a stop sign, figured I was too close so I put it in reverse (from drive, haven't been to "park" yet) to get some space between myself and the intersection. No reverse. Back to drive - now no drive either. Shut the car off, re-started a few minutes later, still not engaging in any gear. Tried drive, 3, 2, reverse, etc. Every gear is neutral. I replaced the range switch, but that wasn't the problem. Got the car home (yay AAA), and unhooked a fluid line to check for flow. No fluid flow. Dropped the pan to change the filter, plenty of fluid (was full on dipstick before I drained), and the pan/fluid was surprisingly clean. No debris in the pan, fluid wasn't burned. Just looked like old fluid, still a slight pinkish tint and no weird smell. Roughly 200k on trans, and about 110k since last fluid change, although I did add a few quarts of new fluid last year when I installed an external cooler thinking it was the tranny just getting hot and causing this issue. :-/

Replaced the filter, added new fluid, still nothing. Trans won't engage any gear, and no pressure at the cooler.

Oil pump? Torque converter? I have no idea where to go from here, and don't want to rip it out to replace something internal, only to discover it isn't the issue. Hoping it's a simple fix, but it's looking like I'll be dropping the trans and taking it to a shop.

Any ideas?

Cliff's notes:
Not engaging any gear
replaced range switch, no dice
no fluid flow/pressure at trans cooler
replaced filter and fluid, no dice
many beers were had.

EDIT: Also, no codes. Granted, I don't have a Tech II, but I do have the DHP and a bluetooth OBD reader for my phone.
Click to expand...


seems like a clogged cat. if you were to floor it longer i bet the cel would flash, but dont do that, its not good for the car at all. drive it at night and see if the cat glows red, or the manifolds start to cherry up.
 


Peder said:
Yep. I don't understand it either. lol
Click to expand...

found these two posts for you. http://www.grandprixforums.net/p1810-trouble-code-tfp-valve-position-switch-circuit-5118.html

P1860 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat

it is possible to change the solenoids in the side cover with out fully removing the trans, you need to remove the d/s axle and then drop the sub frame on the d/s a bit as well. saw a vid on youtube who did it this way, (of course i cant find it now) of a guy who had it all broken down and apart, its best to change the harness as well.
 
thanks Scottydoggs, I have seen that post and tried to unplug the trans connector to see if anything changed but no dice. also it went from shifting fine to zero all at once? seems a little different.
 
the round plug high on the side of the trans, you need to squeeze it and then pull it off. the left and right side.

there are 2 more plugs further down where the shiftier cable mounts to the trans.
 


Searching here for trans/info under my name has a ton of info as well.

I'd check the resistance of the soleniods first on the OP trans

On the other one w/o pressure, you likely broke a pump shaft.
 
Thanks Bill I've learned a lot from you over the course of the engine trans swap so just wanted say much appreciated!

I tried to ohm out the solenoids but really couldn't get any consistent readings plus it was snowing... I did however find a shop that would do a free diagnosis so we drug it over to them.
Got a call from the shop saying they read all kinds of codes of the transmission, not sure why my Amazon special only read two but I don't think he is lying. His best bet is that the clutch plates are shot...

Not a happy camper as I paid top dollar for a used motor trans because the trans had a gm remanufactured sticker on it.

Anyway $2400 to rebuild it..... got me to thinking which isn't always good but.
I still have the standard 4t65e non HD trans that was in the car with 70K miles on it when the motor went to hell.
If I swapped the transaxle from the HD unit assuming it is OK into the original trans what trouble would I have with the car? Would the different gear ratios be a problem or the shift points etc?
I realize we could forgo this but my son has ideas of building the car up so if I am going to do it I figured might as well really do it.. Or do I try to purchase another junkyard unit not so sure about that anymore but if the price was right maybe that is the thing to do?
 


Is it hard to do the solenoids with it in the car still, mine won't shift into 3 or any higher gear but shifts fine through first and second. Just stays in second and revs out...
 
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