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Ask sprinkles08 Your Own Question
sprinkles08, ASE Certified Technician
Category: Chevy
Satisfied Customers: 21435
Experience:  ASE Master and Advanced level certified. Factory trained with 15 years dealership experience
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My 05 lly duramax wont crank, I can run a jump wire to the

Customer Question

hi pearl, my 05 lly duramax wont crank, I can run a jump wire to the starter and get it to crank(still wont start) but wont from a key. checked relays and they are good.
JA: How many miles are on the car? Has the car been starting normally?
Customer: 208,000 and yes, I towed a tractor with it, shut it off then 3 days later of sitting it wouldn't crank
JA: What is the model/year of your Chevy?
Customer: 2005 gmc 2500 duramax lly
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: yes I am. battery voltage, relay a fuses, wiring harness, jump wire the starter
JA: Anything else you think the mechanic should know?
Customer: the ecm is tuned with duramax tuner
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Chevy Mechanic about your situation and then connect you two.
Submitted: 3 months ago.
Category: Chevy
Expert:  sprinkles08 replied 3 months ago.

Hello and welcome to JustAnswer!

There are many things that could cause what you're having but if you're unable to crank it with the key and it doesn't start when jumping the starter then I first suspect the ECM is down. This could be due to an internal failure or a loss of power or ground to it.

Do you have a scan tool to check for ECM Communication?

Customer: replied 3 months ago.
Pcm p0098 pcm p3B00 pcm p15A5 are three codes that came up when I scanned it. I don't have a full scanner but a efi live scan tool. I have 12v coming to the ecm in the fuse box and you can hear the relays close when you inert the 20A fuse back onto it's spot with the key on.
Expert:  sprinkles08 replied 3 months ago.

Do you have the VIN?

Customer: replied 3 months ago.
1GTHK29245E316864 that is the Vin
Expert:  sprinkles08 replied 3 months ago.

Do you have another code reader or scan tool available? The codes you posted don't show valid for this vehicle.

Customer: replied 3 months ago.
No I don't. When I turn the key, the security light comes on and the battery light but no check engine light
Expert:  sprinkles08 replied 3 months ago.

I would recommend trying to come up with another scan tool or code reader because these are not valid. They're either being reported incorrectly or are setting because of an internal failure in the ECM.