Started running rough out of nowhere?

Tiny
R$R
  • MEMBER
  • 2004 PONTIAC GRAND AM
  • 3.4L
  • V6
  • 2WD
  • AUTOMATIC
  • 190,000 MILES
My car listed above started driving rough out nowhere. It seemed like it wasn't shifting properly and my speedometer stopped work I still had all other gages working just fine so I parked it for a bit and had it towed to my house about a month after it happened and replaced the PCV check valve and line going from the crank shaft to the intake and I replaced the PCV solenoid as well and went to test drive it and it was stuck in 2nd gear and wouldn't shift out of 2nd gear. There's no trouble codes or worry lights on at all. I tested the alternator, and it was keeping consistent voltage. Is there any way you could send me the repair manual pdf?
Tuesday, November 5th, 2024 AT 7:07 AM

8 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
If the speedometer stops working the transmission will not shift gears, 9 times out of 10 it will be the VSS (vehicle speed sensor), here is the location so you can change it out. They call it an output shaft speed sensor, but it is the same thing. Check out the images (below). Please let us know what happens.
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Tuesday, November 5th, 2024 AT 1:15 PM
Tiny
R$R
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  • 14 POSTS
Well, I actually did replace the output speed sensor about 10 months ago because I was replacing the wheel speed sensors and figured why not but I didn't know the transmission won't shift when the speedometer not working. Is there any sensors or fuses for the speedometer?
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Tuesday, November 5th, 2024 AT 1:24 PM
Tiny
R$R
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  • 14 POSTS
I replaced the wheel speed sensors because I had the ABS and traction control lights on.
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Tuesday, November 5th, 2024 AT 1:25 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
The new output speed sensor can be defective but here are the fuses and ground I would check for the instrument cluster. This guide can help you check for power and ground:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the images (below). Please let us know what happens.
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Wednesday, November 6th, 2024 AT 9:22 AM
Tiny
R$R
  • MEMBER
  • 14 POSTS
That's what I was think after I sent that lol. I'll let you know when I figure something out. I appreciate it! Is there any way I could get a pdf of the repair manual?
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Wednesday, November 6th, 2024 AT 12:43 PM
Tiny
R$R
  • MEMBER
  • 14 POSTS
Could I get the headlight wiring diagram? Because, looking at this one is making me think I have a bad body control module. Because I took it into Valvoline one time, and they told me my driver side headlight was getting too much voltage and that its like its stuck on high beam. I also noticed right before it stopped working properly, every time I'd take a left turn, and my wipers would literally stop also I have a random coolant leak that I can't quite pinpoint, so my coolant light randomly turns on and off, but it started happening more frequently before it broke.
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Wednesday, November 6th, 2024 AT 1:16 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
We started on running rough now we are at headlights. Sorry, we only handle one problem per thread, please post your new question here, you must be logged in.

https://www.2carpros.com/questions/new

Cheers, Ken
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Thursday, November 7th, 2024 AT 5:02 PM
Tiny
R$R
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  • 14 POSTS
Understandable. I'll post updates here when it's fixed or if I have to work on the transmission.
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Friday, November 8th, 2024 AT 3:54 PM

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