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97 STS
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Discussion Starter · #1 ·
Are there any known electrical gremlins that cause random stalls? Late last week the car stalled while driving 2X and at a stop 1X. Work at a dealership and have our best troubleshooter on it (stalled 2X on him as well), but we are stumped. FP with key on is 48.5, while driving maintains 40+. Car acts like a no-spark situation when it stalls. There have been no SES codes.

Any ideas?
 

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Discussion Starter · #3 ·
Sorry for the late response Ranger, had already gone to bed. (The saying "early to bed, early to rise..." is way over rated! I have had a cold all winter, can't find two nickles to rub together, and obviousely don't know bupkis.)

We ruled out TB and vacuum. And to top it off, we can not get the car to repeat the failure now. I am driving with tattle tail lights off of the relay block and FP meter. It really acts electrical when it does fail. Just kills all spark (or that feeling). We did find a wire bundle rear center at the crossbar that was rubbing. It is the harness for ERC and, according to the tech, should not be related. I get real nervous when problems seem to disappear on their own.
 

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2010 DTS
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88,120 Posts
Intermittent electrical problems are the worst.Might check the connections on the ICM.

What's an "ERC"?
 

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97 STS
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Discussion Starter · #5 ·
Sorry for the ERC. ESC is what I was referring to. There should be no relation to the harness (something around an 8+ wire group) and my issue should there?
 

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Discussion Starter · #6 ·
Re: Might check the connections on the ICM.

I am wondering if the tech may have moved something there (ICM) and "solved" the issue without knowing. I need to keep the tubes and wires hooked up to her for a few days to make sure. They don't call them gremlins for nothing.
 

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2010 DTS
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OH ESC! Now I understand. :duh:

It's possible if someone worked on it they may have tightened a connection or ground without realizing it.
 

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1997 Cadillac STS (BOSE w/AUX In, Massage Seats, URPAS, "Z")
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6,405 Posts
If the car stalls should be AT LEAST one code: Engine stall or near stall detected. Pull your codes, if there was something now is a history code.
 

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97 STS
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Discussion Starter · #9 ·
@N*Caddy,

All codes have been pulled and no smoking guns unfortunately. The best was a lean code (most likely caused by the car stalling).
 

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Discussion Starter · #10 ·
I want to keep this thread alive as I will keep updates on progress and the final diagnosis. Today we discussed the status (tech and myself) . He had a hunch on a fuse block related cause due to the disappearance of the problem when the test leads took over the FP relay. No time to look at the car today, but will keep all informed as problems are identified and/or solved.

I have avoided a FP replacement that retails in excess of $500 so far.
 

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Discussion Starter · #12 ·
@ N*Caddy,

48.5 at key on is solid as granite. 40+ includes start/stops, hard turns, ease offs, and FTTF (foot to the floor). I have been testing this thing to make it replicate for 3 days now. It is my wife's day driver as it gets 19.4mpg on average (not bad for a 97). But I do not want her left on the side of a road if something fails.
 

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1,558 Posts
i have tht same exact problem on my caddi sts 96. the thing is the mas airflow sensor and the idling sensor. replace both and ur good. its prty costly. both together are like 400 parts alone. i got mine from a junkyardd at waaaaaay less. but works just fine.
 

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Discussion Starter · #14 ·
Problem resurfaced. We have not had time to troubleshoot at the dealership and I have kept the monitors in place.

When the car stalls it acts like the fuel pump has been turned off by a light switch. PCM is acting just the way it should (keeps a 2 Sec delay then shuts off circuit). Am I looking for a ground issue? Perhaps something related to the fuse block?
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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Not usual for a pre-2000 engine, but a CKP (CranKshaft Position sensor) fault will act exactly like the "fuel pump has been turned off by a light switch", particularly during warmup slow speeds and coastdowns to stop.

There are two such sensors in your engine - front side, lower block, just right of the oil filter adapter.
 

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Discussion Starter · #16 ·
"and coastdowns to stop" This may be the smoking gun. I have asked the tech about the CKPs and they were poo pooed. But the coast to stop is 80% of the failures.
 

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Discussion Starter · #17 ·
Resolution at last!

The problem was the connector at the top of the FP (replaced the FP anyway). Lovely MN winters prompt a great deal of salt being tossed onto the road and ultimately the undercarraige of vehicles. The connector corroded ever so slightly to create an intermittent short.

Thanks for all the advise !
 

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1996 Eldorado
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My car stalled once after appyling the brake, a loose corroded battery cable caused this. no codes.

I would suspect a CKP but believe that would use leave DTC history data.
 
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