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Im working on a 2001 cat 3126. Died while driving cranks but…

Im working on a 2001...
Im working on a 2001 cat 3126. Died while driving cranks but no start. No communication on pro link. engine serial #ckm19576
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Answered in 1 minute by:
4/28/2015
Technician: Cat Man, Cat Engine Expert replied 7 years ago
Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 10,344
Experience: I am ASE Master Truck Certified.
Verified
Hi. Thanks for asking your question! I will try and help you out.
Does the yellow check engine light come on when the key is turned to the on position?
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Customer reply replied 7 years ago
No check engine light. It does have a check trans light and abs light. I don't have the code number in front of me but it refers to engine speed reasonableness.im repulling codes now.
Technician: Cat Man, Cat Engine Expert replied 7 years ago
Thanks for the information.
If the yellow check engine light does not come on when the key is turned to the on position and the engine will not start, there are only 2 things that can cause this.
The first and most common is the engine ECM is not getting the correct power and ground to function. The ECM should have power on pins 52, 53, and 70 of the rear most ECM connector. This is the truck side harness connector. 70 is the key switch wire. The grounds are on pins 65 and 67. You can remove the connector and check for power on these pins. If you do not have power on these pins, you most likely have a blown fuse in the electrical system. I would check all fuses first.
If you do have correct power and ground to the ECM, you most likely have a failed ECM. I have seen this many times over the years. To confirm the ECM is bad, you would need to install a known good ECM on the engine or you can take the ECM to the dealer to be tested. Unfortunately the ECM cannot be repaired. Replacement is the only option. I am sorry. I wish I had better news.
Please reply back if you need more help or have more questions. I am happy to assist.
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Customer reply replied 7 years ago
I suspect loss of power to ecm on battery or ign ckt. confirmed power on pins 52 and 53 and good grounds on pins 65 and 67. Pin 70 doesn't get power ever.
Technician: Cat Man, Cat Engine Expert replied 7 years ago
Thanks for the information
Yeah pin 70 is the key switch power. If you have no power there, you most likely have a blown fuse or failed ignition relay.
Let me know if you need more help
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Customer reply replied 7 years ago
With ecm connected and back probing pin 70 jumpered to ignition power still crank no start.
Technician: Cat Man, Cat Engine Expert replied 7 years ago
Thanks for the information.
You may have a shorted out ecm. I have seen this many times. With power on 70. There should be a light and it should start.
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Customer reply replied 7 years ago
Thank you. I suspect the same. just needed some reassurance. Before ecm replacement I would like to confirm ignition wiring ckts at relays. Is it possible to get Thomas schematics.
Technician: Cat Man, Cat Engine Expert replied 7 years ago
You are very welcome. I am happy to help.
Sorry. I don't have any schematics. I wish I did.
Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 10,344
Experience: I am ASE Master Truck Certified.
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