CPS sensor failed repair
Asked by Greenstarfish03 Mar 01, 2019 at 09:11 PM about the 2008 Pontiac Grand Prix Base
Question type: Maintenance & Repair
Hello
I have a 2008 pontiac Grand Prix that started
running really bad and stalling the other day. I got
a scan tool and checked the codes and i had a
crankshaft position sensor performance code and
a cam shaft position sensor code. This seemed
like the cause so I pulled the belt off, removed the
harmonic balancer and put a new crankshaft
sensor in and i figured since it was right there i
also put a new cam shaft sensor in. Put it back
together and i was proud that i manged to take
care of this. I cleared the codes and went for a
test drive. It immedietly started sputtering and
stalled. I hooked the scaner back up and i have a
crankshaft position sensor again and now an
intake cam sensor failure. Did i mess something
up? 2008 with 151,000 miles. The car has beena.
Good car we bought it new. Any help would be
appreciated.
24 Answers
Hornet_2497 answered 5 years ago
I went cheap once and my $10 part didn't get too far. If you got a generic part, take it back and get a name brand. Also, the crankshaft position sensors are to be installed with a minimum clearance to produce a strong signal to the ignition. The ones that aim at the flywheel are set to touch, then pull it back 0.030 inches clearance. Tighten fastener. Failure code is P0320. Camshaft position sensor failure code is P0340. Replace them both and rescan after a while, see how it runs. Good Luck.
Greenstarfish03 answered 5 years ago
I dont think I used cheap parts. Both sensors were duralast from autozone. I slid the crankshaft position sensor on the post and fastened both screws. How do i know if my sensor needs to be installed with a gap or tight up against the fly wheel? Is there a way to test my sensors atter i have them off so i can tell if its the sensor or something else? The cam sensor seems impossible to.mess up, butbis there anything special about the cranks sensor i may have missed? Thanks
Greenstarfish03 answered 5 years ago
The codes i had initialy were P0336 and P0341. After isstalling both sensors how could i get the same codes again?
Hornet_2497 answered 5 years ago
Duralast is a good name in parts. I use them and never had a problem. Concerning the installation gap, the parts will come with instructions or there will be a spacer glued on the end of the sensor. Naturally, a part is not to be installed rubbing against a rotating flywheel. If I can find any info on this situation, I will post it.
Greenstarfish03 answered 5 years ago
Thanks hornet. Im going back out to take it apart again now. When I get it open I will snap a picture. Is it possible its something else or more likely i just did something wrong when installing the sensor?
Greenstarfish03 answered 5 years ago
After the apparently poor repair here are the codes. Basicaly the same as before the repair.
Greenstarfish03 answered 5 years ago
Then the first code is just a stored version of the cranksensor code.
Greenstarfish03 answered 5 years ago
This is the first repair of this nature i have attempted. I have always done my own brakes, plugs etc. So im fairly handy this is just new for me.
Greenstarfish03 answered 5 years ago
Ok so much easier to take apart this time. Can you see anything weong by any chance?
Greenstarfish03 answered 5 years ago
Sensor is out now i dont know what to do:)
Greenstarfish03 answered 5 years ago
I noticed a difference in the scan before the repair. Look at the green lights at the top in this pic that are red in the post repair pics.
Hornet_2497 answered 5 years ago
I reviewed what you have done and can't think of anything that's wrong. I noticed this sensor is not adjustable for depth so that is set okay. The only thing to do is call the parts store and ask if you can exchange it. It's rare for a new Duralast part to be defective but I can't think of anything else. Check the wires/connector for breaks/corrosion. Maybe someone can help us out here. F_O_R is good at solving tough problems. Maybe the magnet the sensor aims at is broken/missing.
Greenstarfish03 answered 5 years ago
I didnt know there was a magnet the sensor points at. Let me go look. I will send a picture of it wo the sensor in place. Is it possible that its the fuel filter or pump or not with these errors?
Greenstarfish03 answered 5 years ago
The sensor mounts on the post next to the wire harness. Do you see anything missing? I dont where anything would go.
Greenstarfish03 answered 5 years ago
Is it possible that the harmonic balancer is damaged? It looks good but I dont know what to check specificaly.
Hornet_2497 answered 5 years ago
Fuel pump and filter problems generally do not set codes. You might be able to feel around that harmonic balancer for the magnetic spot using a steel nail. I would hope there is one. On small engines I've seen the flywheel magnet fall off when the cement/glue fails......no more spark. You might want to repost this question and see you can get some fresh responses. The most recently posted questions get the most attention. We need F_O_R to look at this. He's #1. I have to go tune up an oil furnace. I will check back later.
Greenstarfish03 answered 5 years ago
Thanks hornet. I will try to repost and see if F_O_R responds.
Greenstarfish03 answered 5 years ago
Any other input is appreciated? I will install new sensors tomorrow morning.
Greenstarfish03 answered 5 years ago
Im not sure if anyone is listening anymore but i put 2 new sensors in and put it back together and then started rhe care and at first it ran smooth. I slowy revd the engine up a few times and it ran smooth then after 5 minutes or so of running it started sputtering and staled then it wouldnt restart. Basicaly as soon as it got warm it stahled. This time i only got the crank shaft sensor code at least so far no cam shaft code. I have no idea waht to do now.
i am having this exact same issue today. Did you ever find a solution?
I'm sure this has been solved by now, but did you ever do the Crank Relearn? lol