'02 Impala 3.4L, 209.4k : P0102 Won't Go Away!

NickD

wrench
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I see that MAP sensor on this vehicle is externally mounted with a neoprene hose that goes into the intake manifold. Not to sound old fashion, but still rely on a compression tester, vacuum gauge, and an oil pressure tester to troubleshoot a vehicle. These are direct measurement instruments that do not depend on a made in China electronic sensor to provide information.

One engine was only getting 30 psi on a cylinder, reason for a misfire, replacing a spark plug would not correct this. Another with a friend laying out 1,500 bucks with a misfire, vacuum was low only 6"/Hg, dealer replaced and charged him for a whole bunch of parts based strictly on codes when he had an intake manifold.

Was even told by a dealer, my rear bumper is not falling off, ain't getting a code was the reason. A bumper falling off code?

Really don't want to say nasty things about GM it was in the later 80's they hire a ton of attorneys, couldn't even speak to another department manager unless an attorney was present, even though most of them lacked any technical knowledge. They also revamped the manual department, elimination any testing specifications that could end up in a warranty claim. How do you test a module? Simple just replace it with one that is good, but I always had the question, how do you know it good unless you can test it, and for this need test specifications.

Designing modules was easy, what was not, designing the test equipment to test it, on some, had to conduct over 300 separate test per second with automatic feed and ejection. If rejected shot into a separate bin.

For most MAP sensors, a five volt power supply, hand vacuum pump, and voltmeter is all you need, recall on a Ford MAP frequency would vary from 90 to 150 by varying the input vacuum from 0 to 20"/Hg, further testing is done in an environmental chamber varying the temperature from -40 to 125*C.

But you don't have to go through all this, just replace it with a known good one per the manual instructions.
 

NickD

wrench
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Messages
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Points
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Plastic nipple broke off my MAP sensor on an 89 Continental, dealer want 70 bucks for a new one. For that kind of money drilled in a hole where the broken nipple was an epoxied in a piece of brass tubing.

To test it out hooked up my hand vacuum pump with a gauge, 5V and a voltmeter, no change in voltage with vacuum, but this is how GM worked.

Hooked up my scope, the output frequency varied from 90 to 153 hertz, weird, but so is Ford. Back in the car, ran perfectly.

Ha, never mind!
 

nickb2

Wrench. Diagnostic Tech.
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Nov 22, 2008
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St-Hyacinthe, Quebec, Canada
Update just for colt hero, I still like harley pedalson. I wiped out on a medalist bike. Ouch!! Two weeks ago, doc gave me off or light labor, I took one day off, back to races with naproxen:D:fixed:
20200524_083022[1].jpg
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
11,016
Points
63
Location
St-Hyacinthe, Quebec, Canada
@ colt, missed you. Hows things?

Worked an 80ish alfa romeo today, what a mess. A spider valenca or something to that effect. Damn thing had a 1994ish volks gti or jetta dizzy. All wiring was given no regards, figure me out italia car said.

Weird thing is, damn thing still ran with these comp numbers.

#1 70psi #2 30psi #3 90psi #4 65psi.

o_O
 
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