Cadillac Owners Forum banner

1 - 14 of 14 Posts

·
Registered
99 Deville, 06 DTS Performance
Joined
·
140 Posts
Discussion Starter #1
P1527 - Transmission Range to Pressure Switch Correlation

on my way to austin the other day all if a sudden it seemed like my transmission was slippiing (it has never done that before) between 50-60 mph at an idle speed. checked the codes and got p1527 which is transmission range to pressure switch correlation (history)

what does this mean? i doubt this is something with the gears as it started just suddenly...the car has 130000 miles and im not going to change the tranny fluid from fear that it could worsen things. don't think i have a leak but im going to check the level later on today. gotta remove the air filter thing to get to the dipstick.
 

·
Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
Joined
·
69,430 Posts
Don't forget that your transmission is a dry sump unit: there will be NO fluid on the stick with the engine OFF. The car must be running at idle , shifted through all positions, placed in P and the fluid brought to halfway up the dipstick hashmark. You can use either DEXRON-III or the new synthetic DEXRON-VI which is 100% compatible with -III.

The 1 - 2 and 2 - 3 shifts are controlled by solenoids which set clutch engagement pressures. It's possible that either a solenoid, a band, or the line pressure sensor itself is on the way out. If the code went to History, is the transmission still slipping out of gear on coast down ?? (I think that's what you said your symptom was.......not sure about what the "50-60 mph at an idle speed" means.)
 

·
Registered
99 Deville, 06 DTS Performance
Joined
·
140 Posts
Discussion Starter #3
yes...for instance going uphill at a steady spead of 45-55 major slippage...jerking and such. Also ive noticed now that on a cold start, driving immediately after park causes a major surge forward when it shifts to 2nd. I cleared the code yesterday will check to see if it returns later. It is going to be hard to check the fluid level with the engine at running temp because of the heat of the air filter and such...but i will try to do it by this weekend.
 

·
Registered
99 Deville, 06 DTS Performance
Joined
·
140 Posts
Discussion Starter #4
so this situation just got stranger...at times it will jerk when at a stop light 650 rpm-750 and sometimes not. the code hasn't been re-thrown but its obvious something is wrong. it is getting a pain to drive
 

·
Registered
99STS,2004 Jeep Liberty Renegade,98 Deville RIP
Joined
·
1,054 Posts
This may be something as simple as the transmission range switch, this is located on top of the transmission and tells the pcm what gear the tranny is in, that code relates to a conflict between gears, the tranny is in one and the pcm thinks its in another. I have posted below the code description and it may point you in the right direction...

Circuit Description
This vehicle uses an electronic gear indicator display. There are four inputs which are switches to ground that each have a unique switch pattern. All four of these inputs are housed in the PNP switch and operate together as the Transaxle Range Switch. The PCM uses the combination of the switch patterns to determine the gear selected by the driver. This information is then sent by serial data to the IPC for gear indicator display. When the Conditions for Running the DTC are true this test compares the gear indicated by the Transaxle Range Switch to the gear selected from the Transmission Fluid Pressure Manual Valve Position Switch (TFP switch). If the gear indicated is not the same for both, this DTC is set.

Refer to Engine Controls Electrical Schematic Diagrams for a wiring view of the TFP switch.

Conditions for Running the DTC
Engine running continously for 5 seconds.
Ignition voltage is between 10 and 16 volts.
Transaxle Range switch does not indicate an illegal position.
Transmission Fluid Pressure Manual Valve Position Switch (TFP switch) does not indicate an illegal position.
DTC P1810 has ran and passed.
Conditions for Setting the DTC
The Transaxle Range switch and the Transmission Fluid Pressure Manual Valve Position Switch (TFP switch) indicate different gears for at least 7.8 seconds.

Action Taken When the DTC Sets
The Malfunction Indicator Lamp (MIL) will not illuminate.
No message will be displayed.
Conditions for Clearing the MIL/DTC
A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.
A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
Use a scan tool to clear DTCs.
Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description .
Diagnostic Aids
The modes (circuits) are displayed in order A/B/C/P.
L indicates the circuit low (switched / shorted to ground).
H indicates the circuit is high (open).
 

·
Registered
99 Deville, 06 DTS Performance
Joined
·
140 Posts
Discussion Starter #6
just got this new code today although it was marked history
P1520 - Transmission Range Switch Circuit

so if it is the transmission range switch? how much are we talking? I know a guy that will install a used transmission for 700. if the process of changing out that switch (which im sure it is, its a cadillac) is more than that, should i just replace the transmission?
 

·
Registered
99 Deville, 06 DTS Performance
Joined
·
140 Posts
Discussion Starter #7
also, could some one please describe to me the symptoms of a bad catalytic converter?? i believe mine is either bad or going bad as well.
 

·
Registered
99STS,2004 Jeep Liberty Renegade,98 Deville RIP
Joined
·
1,054 Posts
If you go on Rock auto or somewhere else, all that would be needed is to replace the Park neutral Switch, this is located on top of the transmission and its not hard to do, it would cost around 100 dollars. Check first the wiring going into the switch you may have had some coolant drop on it or some chafing. A bad cat will usually throw codes, therefore check pcm for them, if none then there is no problem, you may have the rotten egg smell, that should clear up when you replace the tranny switch, they are interrelated.
 

·
Registered
99 Deville, 06 DTS Performance
Joined
·
140 Posts
Discussion Starter #9
park neutral switch eh? what are the symptoms of a bad one?
 

·
Registered
99STS,2004 Jeep Liberty Renegade,98 Deville RIP
Joined
·
1,054 Posts
A Trans Range Switch is within the Park Neutral switch, there are four connections that work in different combos to tell the ECM what gear you are in, your codes both point to a bad Park Neutral and the wiring either within the switch or leading to it.
 

·
Registered
99 Deville, 06 DTS Performance
Joined
·
140 Posts
Discussion Starter #11
damn...the part may not be too bad but the labor would be probably. Will look into it
 

·
Registered
99 Deville, 06 DTS Performance
Joined
·
140 Posts
Discussion Starter #12
ok for some reason...i believe that it is not the transmission anymore. the other day it was doing the usual jerking at stand still and after i took off i saw the check engine light light up...while driving it flashed a bit but then stayed on. checked the codes and saw pcm p0300 current: Random misfire. Im pretty sure what i was experiencing (thinking the tranny was swithching in and out of gears while at stand still causing the jerking) also felt like it was running on 6-7 cylinders. I didn't think it was anything with the engine as no codes were ever thrown. Could it be that everything i described above in previous posts be attributed to something engine related as opposed to tranny??
 

·
Registered
99 Deville, 06 DTS Performance
Joined
·
140 Posts
Discussion Starter #13
ok turns out it wasnt anything wrong with the transmission....the engine was misfiring so much that it seemed like the tranasmission. got the check engine light and code p0300...took it to the guy that fixed the head gaskets and it turned out to be cylinder 7, bad plug wire. 45$ later and she is running great again :)
 

·
Registered
1992 seville
Joined
·
10 Posts
1992 cadillac seville transmission

well turns out it is my trans leaking i took it to the shop and it was leaking from the line and it supposedly has a hole in the side of the trans the guy said it looks like i rock flew up on the highway or something and put a hole in the side :crybaby: this is very depressing cuz i bought the car two weeks be4 it broke down and the car be4 that broke down one month later and i havnt worked in over a year and a half... I HAVE NO IDEA WHAT TO DO. I was thinking tho is a hole not repairable i mean even a temporary fix or can it not be welded shut??? im trying to find the cheapest method but the problem is the guy said he checked a statewide locator and cannot find a trans for my car.

if anyone knows of anything that might help or if anyone can find me a trans for my 92 cadillac seville. or a quick temporary solution?
 
1 - 14 of 14 Posts
Top