[nnbrent]

Thank you in advance for any advice on this issue, I'm not very knowledgeable about cars in general but have learned a lot in the past year with the help of a few car savvy friends.

The title pretty well sums up my issue. My 2003 Seville is dying after start up, I've had one code pop up after the 3rd or 4th time of dying (p0507) but after checking it, it was cleared by the auto parts store I went to. It has not given a code since that day despite still having issues.

The car has never died at speeds of 30mph or higher and I've gone weeks without an issue then it'll happen again. Sometimes the idle is higher than it should be and sometimes it dies. I've had it die twice on the way to a repair shop in the morning and in two days of having it they couldn't get it to die once. (Luckily they didn't charge me a dime.)

For quick reference p0507 states

Code Definition: Idle Speed High

Possible Causes:

-Engine Vacuum leak
-Idle Air Control has failed
-MAF sensor is dirty, "skewed"
-PCM has failed
-Throttle plate, throttle shaft or linkage is damaged or sticking
-TP Sensor is out-of-ranged or Skewed high


Thank you for any advice!

 

[Ranger]

Re: 2003 Cadillac Seville sporadically dying after start due to low idle. No code sho

:welcome:

If it only dies at idle, I'd first start with a good TB cleaning.
If it dies while off idle (driving), you might replace the CKP sensors if they are original.
As for vacuum leaks, check the PCV grommet in the rear cam cover and all other vacuum lines.
The plenum duct is a possibility, but it should set a DTC.

 

[nnbrent]

Re: 2003 Cadillac Seville sporadically dying after start due to low idle. No code sho

I'm headed out to my father in laws for Easter here in a few, I'm sure he'll be able to help me clean the TB after festivities.
(I picked up some TB cleaner not too long ago so I have it on hand.) I'll give that a shot and see what happens. Thank you for the quick response!

 

[Submariner409]

If the engine dies during a coastdown to stop or for a slow turn, or just as the emissions systems change loop operation, I would suspect CranKshaft Position sensors (CKP). If it dies during idle, I would suspect IAC and/or throttle body/position sensor.

 

[nnbrent]

Thank you for the suggestion. I stumbled across a post that sounded almost identical to my situation from a few years back and he said he'd tried a few of the options that are listed here as well as suggested by some of my friends/family but the post stated that replacing either the IAC valve or IAC sensor fixed the issue. I'm having trouble locating the post now because I found it at my in-laws and not on my computer.

 

[Submariner409]

Google what you remember from the post - maybe something like "cadillac forums 2003 seville stalls at idle" or "cadillac forums 2003 seville ckp failure" or other ideas, preceded by "cadillac forums ............". You'll stumble across the thread. Look through Tech Tips.

 

[nnbrent]

The car has tripped another code, p1860. Yesterday it throttled high when driving to a job site and also died on me as I backed out of the auto shop that I checked the code at.

P1860

Code Definition: TCC PWM Solenoid Circuit Malfunction

I don't know enough about cars to know if this is a secondary issue or if they are linked. Could it just be a fluke occurrence or something caused due to needing to change out the IAC sensor?

 

[Submariner409]

Before you spend a bunch of money on changing an IAC (you don't simply throw parts at these cars), you might want to clean the TB, IAC, and its bore. Several recent threads on this here, in Deville, Northstar and Tech Tips.

P 1860 has nothing to do with any of your idle or stall symptoms.

These cars have a viscous clutch in the torque converter that, at road load speeds over 43 mph, almost locks the converter stator and rotor to remove the last 300 or so of slip, slightly lowering engine rpm, thus resulting in a 1 or 2 mpg fuel savings. It's an emissions system, too - it will fail the car's emissions test(s).

P 1860 refers to the Torque Converter Clutch solenoid, a $45 item buried $2,000 in labor inside the transmission. If the code P 0741 appears, that refers to the TCC itself - "stuck off" - and that points to failed transmission output shaft seals or torque converter hub surface failure.

There IS a workaround to replace the solenoid without removing the transmission, but it involves removing a LOT of interference and working through a 1" opening in the loosened transmission side cover. it's microsurgery at its finest. If you're not a true gearhead with a shop, tools, and expertise - don't even start.

Google "cadillac forums seville northstar torque converter clutch" or something close.

Are you pulling your codes (yourself) from the car's built-in system and deciphering them with this ????

http://www.cadillacfaq.com/faq/answers/dtccode.html