2001 8.1L No start issue

[Cougar281]

About three weeks ago, my step father said his 01 8.1L Sierra wouldn't start, then after he turned the key off and tried again, it started fine, but the CEL was on. I didn't have any of my usual tools with me at the time so I wasn't able to pull any codes out. Fast forward to last night. I'm back out on Long Island and have my Tech2 with me so I hooked up to pull the history codes that I was expecting to see... But the only code there was P0700. Checked the TCM for codes and not a single one. So the Only DTC in the entire truck is P0700. That alone would not cause a no-start. My suspision, based on teh way it was described, was a bad/flaky crank sensor or a wiring problem related to the crank sensor. I know I had issues with my 04/LBZ when I first swapped it with it occasionally doing the same thing and every time it was the crank sensor causing it.

Assuming it WAS the crank sensor, how many key cycles would it take to clear the code from history? If I'm not mistaken, not all codes take the same number of key cycles to clear.

Does anyone else have any theorys?

 

[Canadian Cowboy]

2001 had a recall on the crank sensor.As for your PO700 code check your TCM connector,the TCM is asking for the MIL to be commanded on.It will stay in the code history for around 120 key cycles.
View attachment GM 2001_8100_crankshaft_sensor_recall.pdf

CC

 

[Cougar281]

Hmm... I will have to get his vin and see if the fix was done. If it wasn't done, since it was a recall, would the dealer still fix it for free? His truck has less that 40k, and his brothers (also an 8.1l 01) has less than 30k.

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[Canadian Cowboy]

Yes
CC

 

[Canadian Cowboy]

Yes
CC

If it falls under the VIN sequence.

 

[Cougar281]

Gotha.. I just posted two vins to check in the vin check section.

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[Canadian Cowboy]

Your VINs are not on the list unless GM extended the VIN sequence.
CC

 

[Cougar281]

Your VINs are not on the list unless GM extended the VIN sequence.
CC

Yeah, I saw that :/ (Found the recall floating aaround the internet). Does anyone happen to have the part number for the bad sensor so I could possibly check the sensor to see if it's an 'improved' one or the bad one?

 

[68skylark455]

Is it possible that by cycling the key and starting it might be the fuel pump? We have had several customers tell us they cycle the key a few times and it starts right up and it has been a bad fuel pump every time. Also the fuel pressure regulators on the fuel rail tend to blow the diaphram out and cause a no start/hard start condition and one more common thing has been the coolant sensor-showing it to be 40*-50* eng temp when its 180*-200* . The codes will stay in the system as history until they are cleared or sometimes a long battery disconnect period. The system does a self check 3 times at the same temp and conditions before turning off the light but it leaves the code in the history.

 

[Cougar281]

ECT Looks fine. He said it did it twice about three weeks ago and hasn't done it since, and when it did, it set a MIL. Since I don't see any fuel pressure PIDs, I would think that if it was the fuel pump or pressure regulator, it wouldn't set a MIL, and/or have other issues such as no power. In the three weeks since it did it, the MIL went away, and the only code anywhere in the truck was the P0700. Other than the times that it wouldn't start, it startes perfectly fine. I've also seen a handful of misfires come across on random cylinders. Not a ton, but some. The reason I suspected the CPS is the symptoms are exactly the same as those my truck had when I had a flaky CPS... I'd get a hard start (extra cranking then fired up with MIL) or no start (crank, no start, turn key off, then try again and it starts with MIL), both cases giving me a crankshaft position sensor DTC. I just wish I had my V2 with me three weeks ago so I could have pulled codes right away...

 

[Cougar281]

Replaced the sensor this morning. Not sure if it's my imagination, but it seems like the truck idles a little smoother now (yes, I did a CASE relearn). The sensor that came out was part number 12556427, the new one from Napa, which was a GM part in an Echlin box (and over-priced to boot! $104 from Napa... GM says $88 list!), part number 12575172.

Is there any way to find out if that part number would have been included in the recall and if GM would reimburse the cost of the part?