The Oldsmobile Connection

[schippa2]

I'm getting a few codes from my 1990 Trofeo. They are:

E022 - Throttle position sensor, voltage too low (<0.2v)
E031 - PRNDL switch (wrong parity or selection does not match speed)
E041 - Cam sensor circuit (cam position sensor)

The engine is the 3.8 V6, vin "C." I don't know where any of these sensors/switches are located so please help me out.

[Turbocharged400sbc]

the TPS is located on the throttle body on the oposite end of the throttle blade/shaft as your throttle/cruise control cables are mounted
this is usually a 3 wire sensor 5v/signal/ground and very poss it is just worn out (unless critter chewed up wires lol)
the PRNDL or transmission range switch is located on top of the tranny over the shaft that the shift lever is bolted onto you will see your shifter cable go to the arm with a black housing with4 or more wires coming out of it (if you look while someone moves the shifter lever you will see it right away) these are also possible to be bad just from old age/critter chewed through wires LOL (we git that allot in IL)
now your last one is a doosie! best to have it propperly diagnosed as the sensor is it the timing cover above the crankshaft dampner and it senses the magnet that is bolted onto the cam gear.
now several problems can happen to trigger this code, the sensor went bad (not often, but poss) wires got chewed through (by critter or an accesory drive pulley lol) or more often than not the plastic cam gear teeth have broken off and the jaring of a really loose timing chain/loose piece of plastic has knocked the magnet out of it's holder (seen a few of these) or very likely that the magnet has gotten weak with age and can no longer trigger properly (had to pull a cover back off again because of this-so now i replace it whenever i have the cover off doing a Tchain/timing cover gasket)
this is a big undertaking for some people pulling off the Timing cover/dampner etc plus you will need a DSO (Digital Storage Occiliscope-the easiest way) scope to check the signal output from the cam sensor (weak/eratic/no signal etc)and check it's timing in relation to the 7x crank sensor.
this sensor (failure) will not cause a no start but it will place ignition timing (ESC electronic spark control) in a limp home mode.
I would recomend proper diagnostics for all of these codes but if ya want to do a part swap with all of em you can try... and see if the codes come back (after erasing) but i have a feeling further diagnostics are required fer the cam signal problem.
hope i could help
schlim

[schippa2]

Ok, the TPS is easy to get to, I haven't looked for the PRNDL though... can I see it by looking down with the hood open or do I have to get under the car? I think I'm going to hold off on the cam sensor cause I guess I have to take it to a dealer, huh? And what does the car do with the information it gets from that sensor? The engine seems to run perfectly fine without it. Sorry for the million questions, Turbocharged400sbc and thanks for helping me out.

[Turbocharged400sbc]

the tranz position sensor (PRNDL) is viewable from above but ya might have to yank the air cleaner/throttle body tube off to git a better look
you will see the shift arm right away if ya have someone move the shifter inside the car as ya look at it the sensore is under the arm (it unbolts) and the sensor gets unbolted and lifted off and the new one dropped on with the alignment teeth in the correct position then IROR (instalation is reverse of removal)
the cam sensor is what tells the PCM/ECM which cylinder is at TDC and helps it determin ignition timing requirements without it the computer reverts to backup spark maps (called limp-home mode) so the engine isnt making the max power available but it's not bad.
and ya dont have to go to a dealer to git that fixed (unless ya want ta git bent ovr) find a good independant shop (talk to people there's always a good shop around-though maybe not as pretty/clean as the dealership LOL)
glad to help ya
Turbo aka, Schlimthecarguy@comcast.net

[schippa2]

Well Schlim, I went to the auto parts store today and the guy looked confused when I told him I needed a transmission range switch / PRNDL switch. He said the only kind of switch they had for my trans was a neutral safety switch. Is this the same thing? Thanks,
Barry

[Turbocharged400sbc]

yes it is, however the parts person needs to learn a little more about part terms, the range switch does function as a neutral safety switch (keeps ya from starting the engine in gear-only N and park) but it's only job is to tell the ECM/PCM what possition the gear selector is in and the ECM makes the decision from there. older range switches had a dedicated P/N circuit just for the starter relay AND a range switch i doubt yours has this older switch but ya never know without sticking me eyeball on it LOL
Gotta go now, as i need to git up at 5 am to begin my long (2300 miles)drive from ElCajon CA to Palatine IL (my home) in a 68 F250 (I love rust free vehicles! and i bartered fer it-500$ worth of work on a car/RV!) towing my 84 Toyota Cressida (basically a supra wagon (I6 RWD)) loaded with allot of new tools and toys (been helping my packrat GP's move to TX and i am getting my Grumps tools-a few anyway, where there's a will i want to be in it-i git all of his tools when he passes-he and my father really ignited my Psychotic Gearhead nature!
I WILL BE BACK! just dont know if it's in 1 week or two (i am driving an old ford after all LOL...)
Schlim

[schippa2]

Thank you Schlim, wherever you are... I went back to Advance auto and got the switch, the friggin thing cost $108! I installed it today and it took me 4 hours. I initially thought I'd have to remove the ABS unit from the firewall but thank God/Bob I just had to remove the cruise selenoid (i think that's what it was) and a very large bracket. Working space was very tight, but I got it done. Now the ultra annoying "Gear select problem - check gear shift position" message does not pop up on the VIC every 2 minutes or so with the accompanying ding-ding-ding noise. And it only tells me if a door is open or if the E-brake is engaged when the car is in gear, instead of all the time (something that was also extremely annoying). Taking it out on the road, it seemed to shift more intelligently.

Inheriting tools is awesome. My dad inherited all of his father's tools when he passed away in the early 80's, he was a mechanic too... which means two big tool chests filled with anything you could ever need, and it's all old Snap-On and Craftsman stuff, guaranteed forever. You don't know how lucky you are until you go to a buddy's house and all he has is a little plastic box with a $20 ratchet set and some assorted neon-handle screwdrivers. Anyways, good luck on your road trip and lets see some pictures of that truck!

[Turbocharged400sbc]

Back again, schlim is back
2300 miles in a 68ferd f250 -not bad!
replaced a u joint near Oaki city Oakiland and poped the rad in IL! at least it waited to pop when i was 180 miles from home instead of podunk usa!
I loved cruisin old rt 66! on the CB half the truck drivers couldnt belive i was driving that far in that truck-ya meet some cool people on a CB.
am hoping to git all caught up (some tornado hit my garage and i gotta clean it all up! and it's cold here in Hangover Park IL!!!! i shoulda brought the lovely Cali weather with me!) and be able to post pics....
schlim
aka Turbo/James

[GraveReaper0]

Welcome back to IL. :-D